PART 1: MACHINE DESIGN SHORT PROBLEMS STRENGTH OF MATERIALS 1.
A horizontal cantilever beam, 16 ft long is subjected to a load of 500 lb located to its center. The dimension of the beam is 2 x 4 inches respectively. w = 100 lb/ft, find its flexular stress. Answer: A A. 3150 psi B. 2912 psi C. 4510 psi D. 5663 psi
2.
A 12 m simply supported beam with 30 KN load at the center has a maximum deflection of: (EI = 6000 KN.m2). Answer: D A. 150 mm B. 160 mm C. 170 mm D. 180 mm
3.
A 10 m simply supported beam with 25 KN load 3m from the left end has a maximum slope at the left end: (EI = 8000 Kn.m2). Answer: C A. 0.0056 rad B. 0.0765 rad C. 0.0186 rad D. 0.1823 rad
4.
A 10 m simply supported beam has a uniform load of 2 KN/m extended from left end to 4 m and has a concentrated load of 10 KN, 2 m from the right end. Find the maximum moment at the 10 KN concentrated load. (EI = 10,000 KN.m2). Answer: A A. 19.20 KN.m B. 26.34 KN.m C. 23.45 KN.m D. 12.34 KN.m
5.
A 10 m simply supported beam with uniform load of 3 KN/m from right end to left end has a maximum deflection of: (EI = 12,000 Kn.m2). Answer: B A. 43.23 mm B. 32.55 mm C. 54.23 mm D. 36.45 mm
6.
A 8 m simply supported beam has a uniform load of 2 KN/m from left end to right end and concentrated load of 10 KN at the center has a maximum deflection of: (EI = 5,000 Kn.m 2). Answer: B A. 12.34 mm B. 42.66 mm C. 21.33 mm D. 34.34 mm
7.
A 10 m cantilever beam has a concentrated load of 10 KN/m at the free end. Find the maximum deflection of the beam. (EI = 7,000 Kn.m2). Answer: A A. 476.20 mm B. 342.34 mm C. 544.34 mm D. 764.44 mm
8.
A 14 m cantilever beam has a concentrated load of 25 KN/m at the mid-span. Find the maximum slope of the beam. (EI = 9,000 Kn.m2). Answer: B A. 0.00234 rad B. 0.068 rad C. 1.23 rad D. 0.123 rad
9.
A 10 m cantilever beam has a uniform load of 2.5 KN/m from left to right end. Find the maximum deflection of the beam. (EI = 11,000 Kn.m2). Answer: D A. 423.45 mm B. 198.23 mm C. 323.45 mm D. 284.10 mm
10. A 10 m cantilever beam has a uniform load of 2 KN/m from left to right end and with concentrated load of 8 KN at the center. Find the maximum slope of the beam. (EI = 13,000 Kn.m 2). Answer: C A. 0.011 rad B. 0.022 rad C. 0.033 rad D. 0.044 rad 11. A 14 m cantilever beam has a load of 16 KN, 6 m from the fixed end. Find the maximum slope of the beam. (EI = 6,000 Kn.m2). Answer: B A. 0.183 rad B. 0.048 rad C. 0.863 rad D. 0.064 rad 12. A 12 m cantilever beam has a uniform load of 1.5 KN/m extended from fixed end up to 4 m and a concentrated load of 8 KN at the free end. Find the maximum slope of the beam. (EI = 8,000 Kn.m 2). Answer: A A. 0.126 rad B. 0.234 rad C. 0.654 rad D. 0.345 rad 13. A 10 m simply supported beam has a triangular load from zero at the left end to a maximum of 10 KN/m at the right end. Find the maximum deflection of the beam. (EI = 10,000 Kn.m 2). Answer: B A. 54.24 mm B. 65.10 mm C. 84.67 mm D. 76.56 mm
14. An 8 m cantilever beam has a triangular load from left end to a maximum of 12 KN/m at the fixed end. What is the maximum deflection of the beam? (EI = 12,000 Kn.m2). Answer: A A. 136.53 mm B. 145.34 mm C. 165.34 mm D. 154.34 mm 15. A 12 m restrained beams with two end fixed has a concentrated load of 15 KN at the center. Find the maximum deflection of the beam. (EI = 7,000 Kn.m2). Answer: C A. 8.45 mm B. 34.23 mm C. 19.28 mm D. 24.67 mm 16. A 15 m restrained beams with two end fixed has a uniform load of 3 KN/m, find the maximum deflection of the beam. (EI = 9,000 Kn.m2). Answer: D A. 56.34 mm B. 23.56 mm C. 34.56 mm D. 43.94 mm 17. A vertical load of 400 N acts at the end of a horizontal rectangular cantilever beam 2 m long and 25 mm wide. If the allowable bending stress is 130 Mpa, find the depth of the beam. Answer: B A. 23.45 mm B. 38.43 mm C. 56.43 mm D. 45.34 mm 18. A simply supported beam is 50 mm by 200 mm in cross-section and 4 m long. If the flexular stress is not to exceed 8.3 Mpa, find the maximum mid-span concentrated load. Answer: A A. 2.77 KN B. 6.34 KN C. 3.45 KN D. 4.34 KN 19. A simple wooden beam, 50 mm wide by 250 mm deep and 7.5 m long has a maximum deflection of 102 mm under a uniform load “w”. E = 12,411 Mpa. A. What is the uniform load, w. Answer: 2KN/m B. What is the slope? Answer: 0.0435 rad C. What is the maximum moment? Answer: 14 KN.m D. What is the maximum shear? Answer: 7.5 KN E. What is the flexular stress? Answer: 26.880 Mpa F. What is the shearing stress? Answer: 900 Kpa 20. A simply supported beam having a span of 6 m carries two concentrated loads of 80 KN at its middle thirds. Compute the deflection at the mid-span due to this load. Let EI = 30,670 x 10 9 N.mm2. Answer: B A. 18 mm B. 20 mm C. 24 mm D. 30 mm
21. A cantilever beam having a span of 6 m, carries a triangular load of 20 KN/m at its fixed end to zero at the free end of the beam. Determine the deflection at the free end of the beam if EI = 50 x 10 12 N.mm2. Answer: A A. 17.28 mm B. 16.48 mm C. 15.62 mm D. 12.63 mm 22. A simply supported rectangular beam 50 mm wide by 100 mm deep carries a uniform load 1200 N/m over its entire length. What is the maximum length of the beam if the flexular stress is limited to 20 Mpa. Answer: A A. 3.33 m B. 4.25 m C. 5.2 m D. 6.0 m 23. A simply supported beam having a span of 20 m carries a concentrated load of 10 KN at a distance of 5 m from the left support and a counter clockwise couple of 6KN.m acting 3 m from the right support. The maximum moment due to this load is: Answer: A A. 39 KN. m B. 43 KN. m C. 36 KN. m D. 48 KN. m 24. A cantilever beam having a span of 4 m carries a concentrated load of 50 KN at the free end. What is the flexular rigidity if the beam deflects 29.63 mm at is free end. Answer: A A. 36,000 KN. m2 B. 42,000 KN. m2 C. 24,800 KN. m2 D. 54,200 KN. m2 25. A restrained beam carries a triangular load which increases from zero to 30 KN/m from A to B having a span of 4 m. Determine the moment A. Answer: D A. 12 KN. m B. 24 KN. m C. 18 KN. m D. 16 KN. m 26. A cantilever beam 3 m long carries a concentrated load of 35 KN at its free end. The material is structural steel and the maximum bending stress is not to exceed 125 Mpa. Determine the required diameter of the bar if it is circular. Answer: A A. 204.5 mm B. 188.6 mm C. 164.6 mm D. 179.2 mm
27. A steel beam 2 m in length is simply supported at each end and carries a concentrated load of 100 KN acting 0.5 m from one of the supports. Determine the maximum bending stress set-up in the beam if the cross-section is rectangular, 100 mm wide by 150 mm deep. Answer: A A. 100 Mpa B. 120 Mpa C. 97 Mpa D. 150 Mpa 28. A beam made of titanium has a yield point of 850 Mpa. The beam has 25 mm x 50 mm rectangular cross-section and bends about an axis paralles to the 25 mm face. If the maximum bending stress is 650 Mpa, find the corresponding bending moment. Answer: A A. 6.8 KN.m B. 8.4 KN.m C. 4.5 KN.m D. 8.4 KN.m 29. A restrained beam having a span of 6 m carries a uniform load of 50 N/m throughout its span. If E = 200,000 Mpa, I = 6080 x 106 mm4, determine the deflection at the mid-span. Answer: A A. 0.14 mm B. 0.25 mm C. 0.36 mm D. 0.48 mm MECHANICS 1.
A car travels with an initial velocity of 10 m/s or 36 km/hr. If it is decelerating at the rate of 3 m/s 2, how far, in meters, does it travel before stopping? Answer: A A. 17 B. 21 C. 19 D. 15
2.
A block weighing 56 lbs rest on horizontal surface. The force needed to move along the surface is 20 lbs. determine the coefficient of friction. Answer: C A. 0.0 B. 0.112 C. 0.36 D. 0.28
3.
A baseball is thrown straight upward with a velocity of 20 m/s. Compute for the time elapse for the baseball to return. Assume for a zero drag. Answer: D A. 1.84 B. 2.21 C. 2.50 D. 2.04
4.
A 114 km/s speed is projected vertically how long will it take to go back to its initial position. Answer: A A. 6.45 hrs B. 1.23 hrs C. 7.23 hrs D. 8.45 hrs
5.
An occupant moves toward the center of a merry go around at 6 m/s. If the merry go around rotates at 6 rpm, compute the acceleration component of the occupant normal to the radius. Answer: D A. 6.79 m/s2 B. 8.29 m/s2 C. 7.54 m/s2 D. 3.77 m/s2
6.
A wheel accelerates from rest with a = 5 rad/sec.sec. Compute how many revolutions are made in 4 seconds. Answer: B A. 5.71 rev B. 6.36 rev C. 7 rev D. 20 rev
7.
What minimum distance can a truck slide on a horizontal asphalt road if it is travelling at 25 m/s. The coefficient of sliding friction between asphalt and rubber is at 0.6. The weight of the truck is 8500 kg. Answer: C A. 44.9 B. 58.5 C. 53.2 D. 63.8
8.
A liquid full is to be rotated in the vertical plane. What minimum angular velocity in radians/sec is needed to keep the liquid not spilling if the rotating arm is 1.2 meters? Answer: D A. 2.26 B. 25.6 C. 3.16 D. 2.86
9.
Compute the speed a satellite to orbit the earth at an elevation of 100 km. Earth’s radius is at 6400 km. Assume no change in gravity with the elevation. Answer: D A. 6320 m/s B. 7120 m/s C. 8740 m/s D. 7985 m/s
10. An elevator weighing 2000 lbs is moving vertically upward with an acceleration of 3 ft/s2. A man standing in said elevator weighs 180 lbs.Compute the tension in the supporting cable under this condition. Answer: D A. 2180 lbs B. 2191 lbs C. 1820 lbs D. 2383 lbs
11. The capsule orbits the earth 180 km above the surface. In what velocity in m/s necessary for a circular orbit to consider the earth radius at 6400 km and 9.2 m/s 2? Answer: C A. 8864 B. 7016 C. 7780 D. 8058 12. A truck skids to a stop 60 m after the application of the brakes while travelling at 90 km/hr. What is its acceleration in m/sec2? Answer: A A. -5.21 m/s2 B. -7.06 C. 6.36 D. 5.76 13. A drop hammer of 1 ton dead weight capacity is propelled downward by a 12 in diameter cylinder. At 100 psi air pressure, what is the impact velocity if the stroke is 28 inches? Answer: B A. 63.2 fps B. 31.6 C. 15.8 D. 47.4 14. A flywheel rotates at 120 rpm or 12.57 rad/sec slowed down to 102 rpm or 10.68 rad/sec during the punching operation that requires ¾ second of the punching portion of the cycle. Compute the angular acceleration of the flywheel in rad/sec 2. Answer: A A. -2.52 rad/s2 B. -2.75 rad/s2 C. 3.15 rad/s2 D. 2.22 rad/s2 15. A 2-ton weight is lowered at a constant acceleration of 2 ft/s 2. What is the cable stress? Answer: C A. 4344.34 lb B. 5344.56 lb C. 3751.55 lb D. 6356.24 lb 16. The speedometer of a vehicle changes from 20 km/hr to 80 km/hr in 10 seconds. Find the acceleration for this period in m/s 2. Answer: A A.1.67 B. 6.34 C. 2.34 D. 8.45 17. A car changes accelerates its speed from 20 m/s to 50 m/s in 10 sec. Find the distance travelled during the period of acceleration. Answer: A A. 350 m B. 500 m C. 400 m D. 600 m
18. A box sliding on a floor has a frictional resistance of 100 N. If the coefficient of friction is 0.3, find the weight of the box. Answer: D A. 222.22 N B. 111.11 N C. 444.44 N D. 333.33 N 19. An object dropped on a gravity travels 300 m after how many seconds? Answer: C A. 5.34 sec B. 6.34 sec C. 7.82 sec D. 10.23 sec 20. An object is projected upward at the rate of 40 m/s. How high will the object rise? Answer: D A. 54.34 m B. 76.45 m C. 65.34 m D. 81.55 m 21. A stone is projected upward from the ground travels a maximum height of 50 m. Find the velocity of stone when it returns to the ground. Answer: A A. 31.32 m/sec B. 54.34 m/sec C. 43.23 m/sec D. 23.45 m/sec 22. An object is projected upward at the rate of 45 m/s at 30 0 from the horizontal. Find the maximum range of projectile. Answer: A A. 178.77 m B. 165.34 m C. 189.34 m D. 109.34 m 23. A capsule orbits the earth at the rate of 6000 m/s. If the radius of earth is 3000 km, find the height of capsule from the surface of the earth. Answer: B A. 435.66 m B. 669.72 m C. 543.23 m D. 785.45 m 24. A car that travels 100 mph reduces its speed 50 mph in 30 seconds. Find the distance travelled by the car until it stops. Answer: A A. 4402.10 m B. 3452.34 m C. 5434.56 m D. 6456.35 m
25. A car travelling at 40 m/s in a radius of 1000 m will have a banking angle of:. Answer: C A. 7.340 B. 183.40 C. 9.360 D. 12.30 MACHINE SHOP 1.
Determine the time in seconds, to saw a rectangular magnesium bar 5 in wide and 2 in thick if the length of cut is 5 in. The power hacksaw does 120 strokes/min and the feed/stroke is 0.127 mm. Answer: B A. 189 B. 500 C. 99 D. 20
2.
In an Oxy-Acetylene manual welding method, to weld a 3 ½ ft long seam in a 0.375” thick steel plate at a consumption rate of 9 ft 3/ft for oxygen and 7 ft3/ft for acetylene. Compute for the total combined gas consumption in ft3. Answer: C A. 189 B. 500 C. 99 D. 20
3.
Compute for the drill penetration in in/min when a drill turns at 1200 rpm and the feed of 0.005 in/rev. Material is steel. Answer: D A. 1.8 B. 3.6 C. 12 D. 6
4.
What is the value in degrees of 1 radian? Answer: C A. 57.490 B. 57.940 C. 57.290 D. 57.920
5.
Compute the manual cutting time in minutes, of steel plate 4 ft by 8 ft by 2.5 cm thick with a hand cutting speed of 3.8 to 4 mm/sec, cutting lengthwise Answer: A A. 10 B. 1.81 C. 0.38 D. 8.16
6.
Compute the cutting speed in fpm of a workpiece with 2 inches diameter and running at 100 rpm. Answer: A A. 52 B. 62 C. 25 D. 26
7.
Compute the cutting speed in fpm of a workpiece with 2 inches diameter and turning at 100 rpm. Answer: D A. 72 B. 102 C. 62 D. 52
8.
Determine the average time to cut by automatic oxyacetylene (machine) crosswise a 4 ft x 8 ft x 4 in thick steel plate. Answer: B A. 6.85 B. 318 C. 10 D. 360
9.
Calculate the rpm for machining a cast iron workpiece 6 inches in diameter. The lowest cutting speed for cast iron is 50 fpm. Answer: C A. 35.3 B. 43.3 C. 33.3 D. 53.32
10. With the arc welding rate of 18 in/min, how long will it take to weld ½ in thick plate by 3 feet long seam? Answer: C A. 3 min B. 1.5 min C. 2 min D. 4 min 11. How long will it take to mill a ¾” by 2” long keyway in a 3” diameter shafting with a 24 tooth cutter turning at 100 rpm and a 0.005” feed/tooth? Answer: B A. 0.136 min B. 0.166 min C. 0.196 min D. 0.106 min 12. How long will it take to saw a rectangular piece of aluminum plate 8 in wide and 1 ½ in thick if the length of the cut is 8 in, the power hacksaw makes 120 rev/min and average feed per stroke is 0.0060 in? Answer: C A. 13.11 B. 14.01 C. 11.11 D. 12.03 13. Using oxy-acetylene welding method to weld a 3 ft long seam in a 3/8 in thick plate at a consumption rate of 9 ft3/ft of weld for oxygen and 7 ft 3/ft for acetylene. What is the total combined gas consumption in ft3? Answer: C A. 51 B. 45 C. 48 D. 55
14. A grinding wheel rotates 1750 rpm and has a surface speed of 2290 ft/min. Find the diameter of the wheel in inches. Answer: B A. 3 in B. 5 in C. 4 in D. 6 in 15. To facilitate the milling (roughing) work of a cast steel material using a 1 ½ inch diameter cutter choose between the two available stock. Find the speed of the cutter in rpm. –high speed steel cutter with a cutting speed of 50 fpm- carbide tipped cutter with cutting speed of 200 fpm.. Answer: B A. 389 B. 509 C. 572 D. 412 16. A piston reciprocates 100 times per minute (single stroke). The length of the stroke is 6 in. What is the average wristpin velocity in ft/min? Answer: A A. 50 ft/min B. 100 ft/min C. 75 ft/min D. 125 ft/min 17. A workpiece turning at 300 rpm has a tangential speed of 15 ft/s. Find the diameter of the workpiece. Answer: A A. 11.46 in B. 15.23 in C. 13.23 in D. 17.34 in 18. A workpiece turning at 20 rad/sec has diameter of 4 in. Find the peripheral speed of workpiece. Answer: B A. 1.23 fps B. 3.33 fps C. 5.23 fps D. 7.34 fps 19. Two plates 4 ft x 8 ft plate ½ in thick is to be joined lengthwise. A welding machine to be used has a welding rate of 20 in/min. How long will it take to join the plates? Answer: C A. 7.34 min B. 1.23 min C. 4.80 min D. 6.45 min 20. A 10 ft long seam can be weld in 10 min. the welding rate is: Answer: B A. 8 in/min B. 12 in/min C. 10 in/min D. 14 in/min
21. A seam can be weld in 3 min. If the welding rate is 15 in/min, find the length of the seam. Answer: D A. 20 in B. 30 in C. 25 in D. 45 in 22. How long will it take to mill ½“by 1.5“long keyway by means of 25 teeth cutter turning at 120 rpm and 0.008” feed/tooth. Answer: D A. 1.23 sec B. 6.34 sec C. 4.23 sec D. 3.75 sec 23. A 5 in long keyway is to be mill at the rate of 0.2 in/min. How long will it take to mill the keyway? Answer: C A. 20 sec B. 15 sec C. 25 sec D. 30 sec 24. It takes 1 min to mill a ¾” x 4” keyway of a hub by means of a cutter having 30 teeth at 120 rpm. Find the equivalent feed per tooth, in/tooth. Answer: D A. 0.00222 B. 0.00444 C. 0.00333 D. 0.00111 25. How long will it take to cut a rectangular plate 4 ft wide by means of a saw that has a speed of 160 rev/min and an average feed per stroke of 0.009 in? Answer: B A. 22.22 min B. 33.33 min C. 55.55 min D. 44.44 min 26. A 4 ft wide x 8 ft long and ½ in thick steel plate is be cut into 4 equal parts crosswise. If cutting rate is 0.02 in/stroke and saw speed is 110 rpm, how long will it take to do the job? Answer: C A. 53.45 min B. 34.23 min C. 65.45 min D. 67.45 min 27. It takes 5 min to cut a plate 20 ft long by means of a saw having a speed of 250 rpm. What is the average feed per stroke of the saw, in/stroke? Answer: B A. 0.534 B. 0.192 C. 0.745 D. 0.342
28. An oxyacetylene cutter is use to cut a 4 ft x 8 ft steel plate crosswise and divided the whole plate into five equal parts. If the cutting rate is 10 in per minute, how long will it take to cut plates? Answer: A A. 19.20 min B. 13.45 min C. 21.23 min D. 17.34 min 29. Using oxyacetylene welding method to weld a 10 ft long seam in a ½ in thick plate at a consumption rate of 10 ft3/ft oxygen and 8 ft3/ft for acetylene. What is the total gas consumption? Answer: D A. 150 ft3 B. 170 ft3 C. 160 ft3 D. 180 ft3 30. A 24 ft2 lateral surface for a cylindrical tank is to be made by joining 2 ft by 2 ft steel plate to form 6 ft x 4 ft. The consumption rate for both oxygen and nitrogen is 20 ft 3/ft using oxyacetylene welding method. Find total gas consumption needed, ft3? Answer: D A. 250 ft3 B. 470 ft3 C. 440 ft3 D. 280 ft3 31. A 10 ft x 20 ft plate is to be divided into 8 pieces 5 ft x 5 ft steel plate by means of an oxyacetylene cutter that has a cutting rate of 10 in per minute. How long will it takes to do the job? Answer: C A. 50 min B. 70 min C. 60 min D. 80 min 1.
2.
3.
MACHINE ELEMENTS Two parallel shafts connected by pure rolling turn in the same direction having a speed of 2.75. What is the distance of the shafts if the smaller cylinder is 32 cm in diameter? Answer: D A. 16.67 cm B. 25.25 cm C. 30.25 cm D. 19.25 cm A lineshaft runs at 360 rpm. An 18” pulley on the shaft is belt connected to a 12” pulley on the countershaft. From a 15” pulley on the countershaft, motion is transmitted to the machine. Compute/ check the required diameter of the pulley on the machine to give a spindle speed of 660 rpm. Answer: B A. 16” B. 12 ¼ C. 10 ½ D. 8 ½
A 5 ft diameter pulley is turning at 200 rpm. Find the speed of the pulley mid-way of the center and outer surface of the pulley. Answer: D A. 20.45 ft/s
B. 30.45 ft/s C. 24.34 ft/s D. 26.18 ft/s 4.
A wheel is turning at 360 rpm. If tangential speed of the wheel is 150.80 ft/s, what is the radius of the flywheel? Answer: C A. 8 ft B. 2 ft C. 4 ft D. 10 ft
5.
Two cylinders rolling in opposite direction has a speed ratio of 3. If the center distance is 40 in, find the diameter of smaller cylinder. Answer: A A. 20 in B. 60 in C. 40 in D. 80 in
6.
Three cylinders A:B:C rolling in external contact has a speed ratio of 4:2:1. If the diameter of cylinder A is 10 cm, find the center distance between cylinder A and C. Answer: C A. 40 cm B. 35 cm C. 45 cm D. 50 cm
7.
Four cylinders A:B:C:D has a speed ratio of 6:4:2:1. If the center distance between cylinder A and C is 30 inches, find the center distance A and D. Answer: A A. 68.57 m B. 83.45 m C. 56.34 m D. 76.34 m STRESSES
1.
A steel rod 30 mm & 800 mm long has an allowance elongation not to exceed 1.5 mm, find the allowable load in KN. Answer: A A. 274 B. 248 C. 316 D. 236
2.
Compute the induced/compressive stress, in kpa, of a steel solid shafting of 50 mm diameter and 800 mm in length that is subjected to an increase of temperature by 80 0 C. Answer: D A. 181,816 B. 242,816 C. 218,182 D. 196,560
3.
Compute for the load in KN on a 3 cm diameter, 100 cm long steel rod if its maximum elongation exceed 0.12 cm. Answer: A A. 178
B. 196 C. 148 D. 287 4.
Compute for the polar section modulus of a SAE 1060 shafting having a diameter of 3 inches. Use a factor of safety of 2 and design stress at 800 psi. Answer: D A. 4.7 B. 6.1 C. 4.2 D. 5.3
5.
Compute the allowable load in KN on a 20 mm x 120 cm long steel rod with a maximum elongation must not exceed 1 mm. Answer: B A. 35 B. 55 C. 66 D. 76
6.
Determine the load in KW on a 25 mm diameter x 1200 mm long steel shaft if its maximum elongation exceeds 1 mm. Answer: A A. 83 B. 125 C. 103 D. 234
7.
The total weight of steel plates ¾” x 3’ x 20’ is: Answer: A A. 1838 lbs B. 1698 lbs C. 3676 lbs D. 1848 lbs
8.
What pressure is required for punching a hole 2 inches in diameter thru a ¼ in steel plate? Answer: D A. 10 tons B. 30 tons C. 20 tons D. 40 tons
9.
A link has a load factor of 0.8, the surface is 0.92 and the endurance strength is 28,000 psi. Compute the alternating stress of the link if it is subjected to a reversing load. Assume a factor of safety of 3. Answer: C A. 8150 B. 10920 C. 9333 D. 7260
10. Determine the minimum mean diameter of a taper pin for use to fix a lever to shaft, if it is transmit a maximum torque of 700 in-lbs. The shaft diameter is 2 inches and the material allowable stresses is 15,000 psi. Use factor of safety of 2. Answer: D A. 7 mm B. 7.2 mm
C. 5.2 mm D. 6.2 mm 11. How many 5/16 inch holes can be punched in one motion in a steel plate made of SAE 1010 steel, 7/16 inch thick using a force of 55 tons. The ultimate strength for shear is 50 ksi and use 2 factor of safety. Answer: C A. 5.8 B. 3.7 C. 5 D.6.2 12. The shaft whose torque varies from 2000 to 6000 in-lbs has 1 ½ inches in diameter and 60,000 psi yield strength. Compute for the shaft mean average stress. Answer: A A. 6036 psi B. 6810 psi C. 5162 psi D. 5550 psi 13. A journal bearing with diameter of 76.2 mm is subjected to a load of 4900 N while rotating at 200 rpm. If its coefficient of friction is 0.02 and L/D = 2.5, find its projected area in mm 2. Answer: D A. 12090 B. 13050 C. 14165 D. 14516 14. A steel tie rod on bridge must be made withstand a pull of 5000 lbs. Find the diameter of the rod assuming a factor of safety of 5 and ultimate stress of 64,000 psi. Answer: C A. 0.75 B. 0.84 C. 0.71 D. 0.79 15. If the weight of 6” diameter by 48” long SAE 1030 shafting is 174.5 kg, then what will be the weight of chromium SAE 51416 of same size? Answer: B A. 305.5 lbs B. 384.6 lbs C. 426.4 lbs D. 465.1 lbs 16. If the ultimate shear strength of a steel plates is 42,000 psi, what force is necessary to punch a 0.75 inch diameter hole in a 0.625 inch thick plate? Answer: B A. 63,008 lbs B. 61,800 lbs C. 68,080 lbs D. 66,800 lbs 17. What is the modulus of elasticity if the stress is 4,000 psi and unit a strain of 0.00105? Answer: A A. 41.905 x 106 B. 42.300 x 106 C. 41.202 x 106 D. 43.101 x 106
18. A 2.5 in diameter by 2 in long journal bearing is to carry a 5500-lb load at 3600 rpm using SAE 40 lube oil at 2000F through a single hole at 25 psi. Compute the bearing pressure. Answer: A A. 1100 psi B. 1000 psi C. 900 psi D. 950 psi 19. It is a problem of expansion and shrinkage of steel material so that the slightly bigger shafting of 2” diameter can be inserted/fitted to the slightly smaller holes of a steel bushing of 1.999” diameter with the following process/material/data to apply: Coefficient of expansion of carbon steel = 0.0000068 “/”0F temperature raised by gas heating = 24.5 0F. Cooling media to use dry ice with boiling point of -109.30F (-78.50C). Shrinkage rate below boiling point is 0.00073 in/in. Determine the final clearance between the expanded steel bushing hole against the shrinkage of steel shaft. Answer: A A. 0.000793” B. 0.000693” C. 0.000750” D. 0.000800” 20. What modulus of elasticity in tension is required to obtain a unit deformation of 0.00105 m/m from a load producing a unit tensile stress of 44,000 psi? Answer: D A. 42.300 x 106 psi B. 43.101 x 106 psi C. 41.202 x 106 psi D. 41.905 x 106 psi 21. What force P is required to punch a ½ in hole on a 3/8 in thick plate if the ultimate shear strength of the plate is 42,000 psi? Answer: D A. 24,940 lbs B. 24,960 lbs C. 24,620 lbs D. 24,740 lbs 22. What pressure is required to punch a hole 2” diameter through a ¼” steel plate? Answer: D A. 10 tons B. 30 tons C. 20 tons D. 40 tons 23. Compute the working strength of 1” bolt which is screwed up tightly in packed joint when the allowable working stress is 13,000 psi. Answer: B A. 3600 lbs B. 3900 lbs C. 3950 lbs D. 3800 lbs 24. What is the working strength of a 2” bolt which is screwed up tightly in a packed jointly when the allowable working stress 12,000 psi? Answer: B A. 20,120 lbs B. 20,400 lbs C. 20,100 lbs D. 20,200 lbs 25. Determine the estimated weight of an A-36 steel plate size ½” x 4” x 8’. Answer: D A. 280 kgs
B. 301 kgs C. 332 kgs D. 297 kgs 26. Determine the estimated weight of an A-36 steel plate size 3/16” x 6’ x 20’. Answer: A A. 919 lbs B. 829 lbs C. 1012 lbs D. 735 lbs 27. A 19 mm stud bolts is used to fastened on a 250 mm diameter cylinder head of diesel engine. If there are 10 stud bolts, determine the pressure inside the cylinder if bolt stress is limited to 50 Mpa. Answer: A A. 288.8 Kpa B. 2888 Kpa C. 3426 Kpa D. 4828 Kpa 28. A 19 mm stud bolts is used to fastened on a 250 mm diameter cylinder head of diesel engine. If there are 10 stud bolts, determine the pressure inside the cylinder if bolt stress is limited to 50 Mpa. Answer: A A. 288.8 Kpa B. 2888 Kpa C. 3426 Kpa D. 4828 Kpa 29. A column supports a compressive load of 250 KN. Determine the outside diameter of column if inside diameter is 185 mm and compressive stress of 50 Mpa. Answer: B A. 200.62 mm B. 201.47 mm C. 216.42 mm D. 208.41 mm 30. A steel hollow tube is use to carry a tensile load of 500 KN at a stress of 140 Mpa. If outside diameter is 10 times the tube thickness, find the thickness of the tube. Answer: A A. 11.24 mm B. 107 mm C. 20.64 mm D. 22.61 mm 31. A 20 mm diameter rivet is used to fastened two 25 mm thick plate. If the shearing stress is 80 Mpa. What tensile force applied each plate to shear the bolt?. Answer: D A. 26.35 KN B. 28.42 KN C. 30.41 KN D.25.13 KN 32. What force is necessary to punch a 30 mm hole in 12.5 mm thick plate if ultimate shear stress is 410 Mpa? Answer: C A. 564 KN
B. 342 KN C. 483 KN D. 983 KN 33. Two 30 mm thick plate is fastened by two bolts, 25 mm in diameter. If the plates is subjected to 50 KN tension, find the bearing stress in bolts. Answer: A A. 33,333.33 Kpa B. 4444.44 Kpa C. 5555.55 Kpa D. 555,555 Kpa 34. A 2.5 inches shaft is subjected to 3 KN-m torque. Find the stress developed. Answer: C A. 48.62 Mpa B. 52.75 Mpa C. 59.68 Mpa D. 38.64 Mpa 35. A shaft when subjected to pure tension developed a stress of 50 Mpa. If the polar moment of inertia is 6.1359 x 10-7 m4, determine the maximum torque the shaft could handle. Answer: A A. 1.23 KN B. 1.68 KN C. 1.84 KN D. 2.48 KN 36. What is the modulus of elasticity if the stress is 300 Mpa and strain of 0.00138? Answer: A A. 217.39 x 103 Mpa B. 200.61 x 103 Mpa C. 220.61 Mpa D. 215.21 Mpa 37. In a 2.0 m cantilevered I-beam, a 2 Mton weight is applied at the free end. If the allowable stress in beam is 110 Mpa, determine the section modulus. Answer: B A. 18.54 in3 B. 21.77 in3 C. 26.83 in3 D. 24.28 in3 38. A 5 KN force acting at the end of a 3 m cantilever beam. If section modulus of the beam is 10 in3, what is the stress induced? Answer: D A. 86,285 Kpa B. 78,318 Kpa C. 29,684 Kpa D. 91,535 Kpa 39. A 6 mm steel wire is 5 m long and stretches 8 mm under a given load. If the modulus of elasticity is 200 Gpa, find the load applied. Answer: C A. 7 KN B. 8 KN C. 9 KN D. 10 KN
40. A steel wire 10 m long, hanging vertically supports a tensile load of 2 KN. Neglecting the weight of wire, determine the required diameter if the stress is not to exceed 140 Mpa and the total elongation is not to exceed 5 mm. Assume E = 200 Gpa.. Answer: D A. 2 mm B. 3 mm C. 4 mm D. 5 mm 41. An iron rod 4 m long and 0.5 cm2 in cross section stretches 1 mm when a mass of 225 kg is hang on it. Compute the modulus of elasticity of the iron. Answer: A A. 176. 58 Gpa B. 169.81 Gpa C. 160.41 Gpa D. 180.26 Gpa 42. A 20 m rod is stretches to a strain of 0.001. Determine the deflection of the rod. Answer: A A. 20 mm B. 25 mm C. 30 mm D. 35 mm 43. A rail having a coefficient of linear expansion of 11.6 x 10 -6 m/m-0C increases its length when heated from 700F to 1130F. Determine the strain. Answer: D A. 2.04 x 10-4 B. 6.05 x 10-4 C. 4.21 x 10-4 D. 2.77 x 10-4 44. What temperature will the rails just touch if steel railroad is 10 m long are laid with clearance of 3 mm at initial temperature of 150C? Use k = 11.7 x 10-6 m/m- 0C Answer: B A. 35.64 0C B. 40.64 0C C. 45.64 0C D. 50.64 0C
45. For a given material, the modulus of elasticity is 100 GN/m 2 in tension and 40 GN/m2 in shear. Find the Poisson’s ratio. Answer: C A. 0.10 B. 0.50 C. 0.25 D. 0.35 46. A 25 mm shaft is keyed to a 300 mm diameter pulley and transmits 3 KW of power. The keyed assembly rotates at 1725 rpm. What is the tangential force at the key? Answer: A A. 1.33 KN B. 5.23 KN C. 2.33 KN D. 8.34 KN
47. What force is necessary to punch a 1 in hole in a 1/8 in steel plate if the ultimate shearing stress is 60,000 psi and the ultimate compressive stress is 80,000 psi? Answer: D A. 34,520.34 lbs B. 8,345.56 lbs C. 12,344.56 lbs D. 23,561.90 lbs 48. A U-bolt supports a load of 6000 lb. The cross section of the bolt has a diameter of ½ inch. How much stress is induced in the sides of the bolt? Answer: D A. 12,734.45 psi B. 14,567.23 psi C. 13,345.56 psi D. 15,278.12 psi 49. A 1 inch diameter shaft has a 2 in diameter collar resting on a support. The axial load on the shaft is 10,000 lb and the thickness of the collar is ½ in. How much shearing stress is induced? Answer: A A. 6366.20 psi B. 4234.56 psi C. 5244.56 psi D. 8456.34 psi 50. A hollow rivet has an outside diameter of 5 mm and an inside diameter of 3mm. If the allowable shearing stress is 400 x 10 6 N/m2, what maximum shearing force can the rivet sustain if subjected to double shear? Answer: A A. 10 KN B. 20 KN C. 15 KN D. 25 KN 51. A vertical load of 400 Newtons acts at the end of a horizontal rectangular cantilever beam 2 m long and 25 mm wide. If the allowable bending stress is 130 MN/m 2, find the depth of the beam in mm. Answer: B A. 23.44 mm B. 38.43 mm C. 30.23 mm D. 43.23 mm 52. A simply supported timber beam is 50 mm by 200 mm in cross section and 4 m long. If the fiber stress is not to exceed 8.3 Mpa and the beam weight is neglected, find the maximum mid-span concentrated load that the beam can support if the 200 mm dimension is vertically oriented. Answer: A A. 2,766.67 N B. 3,233.45 N C. 2,345.56 N D. 1,234.45 N 53. A lap joint consists of steel plate 250 mm by 18 mm in thickness is connected by 4-20 mm diameter rivets. Compute the bearing capacity of the rivet connection if the allowable bearing stress is 210 Mpa. Answer: A A. 302,400 N B. 360,200 N
C. 420,340 N D. 460,240 N 54. A steel hanger of 2 m length is to carry an axial load of 18 KN. If the tensile stress is restricted to 104 Mpa and the elongation caused by this load is restricted to 1mm, what is the minimum crosssectional area the member can have? E = 200,000 Mpa . Answer: A A. 180 mm2 B. 173 mm2 C. 164 mm2 D. 190 mm2 55. A short hollow steel cylinder with a wall thickness of 38 mm is to carry a compression load, applied uniformly on the end, of 7,800 KN. If the allowable working stress in steel in compression is 138 Mpa, then the minimum outside diameter of the cylinder required to safely support the load is: Answer: A A. 512 mm B. 482 mm C. 396 mm D. 460 mm 56. A 25 mm diameter steel bar is loaded in double shear until failure, the ultimate load is found to be 446 KN. If the allowable stress is based on a factor of safety of 3 what must be the diameter of a pin designed for an allowable load of 26 KN in single shear be? Answer: A A. 14.79 mm B. 15.64 mm C. 13.24 mm D. 12.63 mm 57. A steel bar, initially free of stress, is held between rigid supports. Determine the stress in the bar if temperature drops 1300F. K = 6.5 x 10-6 in/0F, E = 30 x 10 6 psi Answer: A A. 25,350 psi B. 26,234 psi C. 24,896 psi D. 23,654 psi
58. A steel rod with a cross sectional area of 16o mm 2 is to be attached between two fixed points 1.25 m apart. If the rod is too short by 0.25 mm, find the stress applied to put the rod back to fitness. E = 200,000 Mpa Answer: A A. 40 Mpa B. 30 Mpa C. 50 Mpa D. 60 Mpa SHAFT 1.
Compute for the twisting moment in in-lb developed when the shaft delivers 20 hp at 1200 rpm. Answer: C A. 1166
B. 915 C. 1050 D. 945 2.
Find the torsional deflection, in degrees, of a solid steel shaft, 110 mm OD x 1.4 m long subject to 3.1 x 106 N-mm torque. The torsional modulus of elasticity is 80,000 N/mm-mm. Answer: D A. 0.221 B. 0.195 C. 0.28 D. 0.21
3.
Compute for the torsional deflection, in degrees, of a 110 mm diameter, 1.4 m long shaft subjected to a twist moment of 3 x 106 N.mm. The torsional modulus of elasticity is 83000 N/mm 2. Answer: C A. 0.27 B. 0.31 C. 0.20 D. 0.24
4.
Find the torsional moment (in Newton-mm), developed when the shaft delivers 20 KW at 200 rpm. Answer: B A. 0.75 x 106 B. 1.0 x 106 C. 1.20 x 106 D. 2.10 x 106
5.
A 102 mm diameter shaft is driven at 3000 rpm by a 300 hp prime mover. The shaft drives a 121.9 cm diameter chain sprocket having 85% output efficiency. Compute the torque in in-lb developed in the shaft. Answer: D A. 5,600 B. 7,100 C. 8,150 D. 6,300
6.
A 3 in diameter short shaft carrying pulleys close to the bearings transmit how much horsepower if the shaft makes 280 rpm? Answer: C A. 991 hp B. 919 hp C. 199 hp D. 260 hp
7.
What power would the spindle 55 mm in diameter transmit at 480 rpm stress allowed for short shaft is 59 N/mm2? Answer: B A. 98.68 KW B. 96.88 KW C. 68.98 KW D. 68.89 KW
8.
A hollow shaft has an inner diameter of 0.035 m and an outer diameter of 0.06 m. Compute the torque if the shear stress is not to exceed 120 Mpa in N-m. Answer: C A. 4,400 N-m B. 4,300 N-m C. 4,500 N-m D. 4,200 N-m
9.
What power would a spindle 55 mm in diameter transmit at 480 rpm. Stress allowed for short shaft is 59 N/mm2. Answer: No correct answer in the given choices. A. 45.12 kw B. 50.61 kw C. 45 hp D. 39.21 hp
10. A small countershaft is 1 ½ inch in diameter and has an allowable stress of 8500 psi. Find the horsepower delivered by the shaft at a speed of 15.7 rad/s. Answer: C A. 7.20 B. 1.4 C. 13.31 D. 14.72 11. Determine the torque received by the motor shaft running at 4250 rpm, transmitting 11 HP, through a 10 in diameter, 200 involute gear. The shaft is supported by the ball bearings at both ends and the gear is fixed at the middle of 8 in shaft length. Answer: A A. 163 in-lb B. 167 in-lb C. 132 in-lb D. 138 in-lb 12. A 16 ft lineshaft has no bending action except its own weight. What power in HP can the shaft deliver at a speed of 200 rpm. Consider that the torsional deflection will not exceed 0.08/ft length.. Answer: D A. 13.2 B. 15.8 C. 24.4 D. 14.6 13. The torsional deflection of a SAE 1040 steel shaft is 0.8 0 in a length of ½ m. The shear stress is 69 Mpa. Compute the diameter of the shaft in millimeter. Steel modulus of elasticity is 79,300 Mpa or N/mm2. Answer: D A. 51 B. 50 C. 75 D. 62 14. Compute the diameter of a solid shaft transmitting 75 Hp at 1800 rpm. The nature of the load and the type of service is such that the allowable S S based on pure torsion is 6000 psi.. Answer: C A. 1 7/7” B. 2 1/16” C. 1 5/16” D. 3 1/8” 15. The shaft is subjected to a steady load of 36,000 lbs at a shear stress of 10,000 psi. Compute the diameter of the said shaft in inches. Answer: C
A. 1 7/8 B. 2 1/4 C. 3 D. 2 3/4 16. Determine the torque received by the motor shaft running at 4250 rpm, transmitting 11 HP, through a 10 in diameter, 200 involute gear. The shaft is supported by the ball bearings at both ends and the gear is fixed at the shaft length. Answer: A A. 163 in-lb B. 132 in-lb C. 167 in-lb D. 138 in-lb 17. Compute the maximum unit shear in a 3 inches diameter steel shafting that transmits 24,000 in-lb of torque at 99 rpm. Answer: A A. 4530 psi B. 3860 psi C. 4250 psi D. 4930 psi 18. Compute the linear shaft diameter to transmits 12 Hp at 180 rpm with torsional deflection of 0.08 degrees per foot length. Answer: B A. 3 in B. 2.35 in C. 5 cm D. 62 mm
19. Compute the nominal shear stress at the surface in Mpa for a 40 mm diameter shaft that transmit 750 Kw at 1500 rpm. Axial and bending loads are assumed negligible. Torsional shearing stress is 28 N/mm2. Answer: D A. 218 B. 232 C. 312 D. 380 20. A hollow shaft has inner diameter of 0.035 m and outer diameter of 0.06 m. Compute for the torque if the shear stress is not to exceed 120 Mpa in N-m. Answer: A A. 4500 B. 4300 C. 4100 D. 4150 21. Design the size of solid steel shaft to be used for a 500 Hp, 250 rpm application if the allowable torsional deflection is 10 and the allowable stress is 10,000 psi and modulus of rigidity is 13 x 10 6 psi. Answer: B A. 5” dia.
B. 4-7/8” dia. C. 4-5/8” dia. D. 4-3/4” dia. 22. A 2-in solid shaft is driven by a 36-in, gear and transmit power at 120 rpm. If the allowable shearing stress is 12 ksi, what horsepower can be transmitted? Answer: C A. 29.89 B. 38.89 C. 35.89 D. 34.89 23. A short 61 mm diameter shaft transmits 120 Hp. Compute the linear speed of a pulley 55 cm diameter mounted on the shaft. Answer: B A. 1796 fpm B. 1870 fpm C. 1766 fpm D. 2106 fpm 24. A hollow shaft has inner diameter of 0.035 m and outer diameter of 0.06 m. Determine the polar moment of inertia of the hollow shaft. Answer: D A. 1.512 x 10-6 m4 B. 1.152 x 10-6 m4 C. 1.215 x 10-6 m4 D. 1.125 x 10-6 m4 25. Compute the speed of the gear mounted on a 52.5 mm diameter shaft receiving power from a driving motor with 250 Hp. Answer: B A. 2182 rpm B. 2282 rpm C. 2071 rpm D. 2341 rpm 26. A solid cylindrical shaft 48.2 cm long is used for a transmission of mechanical power at a rate of 37 KW running at 1760 rpm. The SS is 8.13 Mpa. Calculate the diameter. Answer: D A. 30 mm B. 40 mm C. 35 mm D. 50 mm 27. A hollow shaft with outside diameter of 14 cm and wall thickness of 0.8 cm transmits 200 Kw at 400 rpm. What must be the angular deflection of the shaft if the length is 5 meters? The material of the shaft is C4140 steel. Answer: B A. 0.84 deg B. 1.14 deg C. 1.83 deg D. 1.50 deg 28. A 3” diameter short shaft carrying 2 inches pulleys close to the bearings transmit how much power if the shaft makes 280 rpm. Answer: A A. 199 Hp B. 200 Hp
C. 198 Hp D. 210 Hp 29. A step shaft made of SAE 1117 steel with an ultimate strength of 69.7 ksi. The notch sensitivity factor is 0.00435 is the constant dependent upon the ultimate strength, check the radius stress raiser. Answer: C A. 0.192 B. 0.386 C. 0.250 D. 0.775 30. A shaft is used to transmit 200 Kw at 300 rpm by means of a 200 mm diameter sprocket. Determine the force tangent to the sprocket. Answer: D A. 60.44 KN B. 60.33 KN C. 60.88 KN D. 63.66 KN 31. Find the diameter of a steel shaft which will be used to operate a 110 Kw motor rotating at 5 rps if torsional stress is 90 Mpa. Answer: B A. 60.2 mm B. 58.3 mm C. 38.3 mm D. 46.2 mm 32. What is the speed of 63.42 mm shaft that transmit 75 Kw if stress is not to exceed 26 Mpa. Answer: A A. 550 rpm B. 660 rpm C. 650 rpm D. 650 rpm 33. A steel shaft transmits 50 Hp at 1400 rpm. If allowable stress is 500 psi, find the shaft diameter. Answer: B A. 3.58 in B. 2.84 in C. 1.65 in D. 2.54 in 34. A hollow shaft that has a 100 mm outside diameter and 80 mm inside diameter is used to transmit 100 Kw at 600 rpm. Determine the shaft stress. Answer: A A. 13.73 Mpa B. 16.82 Mpa C. 19.86 Mpa D. 17.21 Mpa 35. Determine the length of the shortest 2 mm diameter bronze wire which can be twisted through two complete turns without exceeding a shearing stress of 70 Mpa. G = 35,000 Mpa. Answer: A A. 6,283 mm B. 5,484 mm C. 4,836 mm
D. 7,263 mm 36. A hollow shaft developed a torque of 5 KN-m and shaft stress is 40 Mpa. If outside diameter of shaft is 100 mm, determine the shaft inner diameter. Answer: D A. 68.43 mm B. 63.28 mm C. 58.38 mm D. 77.64 mm 37. What is the polar moment of inertia of a solid shaft that has a torque of 1.5 KN-m and a stress of 25 Mpa? Answer: B A. 2.46 x 10-6 m4 B. 2.02 x 10-6 m4 C. 3.46 x 10-6 m4 D. 1.24 x 10-6 m4 38. A force tangent to a foot diameter pulley is 5 KN and is mounted on a 2 inches shaft. Determine the torsional deflection if G = 83 x 106 Kpa. Answer: A A. 0.805 0/m B. 0.654 0/m C. 0.768 0/m D. 0.938 0/m 39. What is the minimum diameter of a steel shaft which will be used to operate a 14 KN-m torque and will not twist more than 30 in a length of 6 m? ( G = 83 x 106 Kpa) Answer: C A. 100.64 mm B. 96.80 mm C. 118.45 mm D. 120.72 mm
40. A solid shaft 5 m long is stressed to 60 Mpa when twisted through 4 0. Find the shaft diameter if G = 83 Gpa. Answer: D A. 95.64 mm B. 90.42 mm C. 101.32 mm D. 103.54 mm 41. What is the diameter of a line shaft that transmit 150 Kw at 15 rps? Answer: A A. 2.28 in B. 3.54 in C. 1.62 in D. 2.04 in 42. A main shaft has 50 mm diameter is running at 300 rpm. What power that could be delivered by the shaft? Answer: B A. 3.40 Hp B. 28.60 Hp C. 32.50 Hp D. 16.42 Hp
43. A 1.5 in diameter short shaft is used to transmit 44.4 Hp. Determine the shaft speed. Answer: B A. 500 rps B. 8.33 rps C. 400 rps D. 450 rps 44. A 3 in solid shaft is desired to replaced a hollow shaft having 4 in outside diameter. Consider the strength to be the same, determine the inside diameter of hollow shaft. Answer: C A. 2.5 in B. 3.0 in C. 3.48 in D. 4.0 in 45. A motor is used to drive a centrifugal pump that discharges 3000 li/min at a head of 10 m. The pump efficiency is 68% and running at 550 rpm. Find the torsional stress of shaft if shaft diameter is 35 mm. Answer: D A. 13.85 Mpa B. 11.85 Mpa C. 12.85 Mpa D.14.87 Mpa 46. A circular saw blade has a circular speed of 25 m/sec and 500 mm diameter is driven by means of belt that has an efficiency of 95%. Find the required diameter of the driven shaft. If power transmitted is 50 Hp. Answer: B A. 1 in B. 2 in C. 3 in D. 4 in
47. An 800 mm diameter circular saw blade is driven by a 1800 rpm motor with belt speed ratio of 1.8. Find the peripheral speed of the blade. Answer: A A. 137.43 ft/sec B. 140.65 ft/sec C. 132.43 ft/sec D. 135.21 ft/sec 48. A machine shaft is supported on bearings 1 m apart is to transmit 190 Kw at 300 rpm while subjected to bending load of 500 kg at the center. If maximum shearing stress is 40 Mpa, determine the shaft diameter. Answer: C A. 100 mm B. 90 mm C. 92 mm D. 98 mm 49. A 100 mm diameter shaft is subjected to a torque of 6 KN-m and a bending moment of 2.5 KN-m. Find the maximum bending stress developed. Answer: A A. 45.84 Mpa B. 60.25 Mpa
C. 50.28 Mpa D. 55.46 Mpa 50. A round steel shaft transmits ½ Hp at 1800 rpm. The shear modulus of elasticity is 12,000,000 psi. The torsional deflection is not to exceed 1 deg in a length equal to 20 times the diameter. Find the shaft diameter. Answer: B A. 1.04 in B. 0.257 in C. 0.864 in D. 2.045 in 51. A line shaft is to transmit 200 Hp at 900 rpm. Find the diameter of the shaft. Answer: B A. 2 3/16 in B. 2 7/16 in C. 3 15/16 in D. 1 3/16 in 52. A centrifugal pump is directly coupled to a motor. The pump rating is 3,600 liters per a minute against a total head of 8 meters of water. Pump efficiency is 65% at a speed of 550 rpm. Calculate the torsional stress induced on the 40 mm diameter motor shaft. Answer: C A. 11,193.45 Kpa B. 13,467.34 Kpa C. 10,010.85 Kpa D. 16,345.67 Kpa 53. A round steel shaft transmits 0.375 Kw at 1800 rpm. The shear modulus of elasticity is 80 Gpa. The torsional deflection is not to exceed 1 degree in a length equal to 20 diameters. Find the shaft diameter. Answer: A A. 6.621 mm B. 8.342 mm C. 12.344 mm D. 16.345 mm 54. A round steel shaft rotates at 200 rpm and is subjected to a torque of 225 N.m and a bending moment of 340 N.m. The allowable shearing stress is 40 MN/m 2, the allowable tensile is 53.3 MN/m 2. Find the dimater. Answer: A A. 6.621 mm B. 8.342 mm C. 12.344 mm D. 16.345 mm 55. A 1 in diameter shaft is to be replaced with a hollow shaft of the same material, weighing half as much, but equally strong in torsion. The outside diameter of the hollow shaft is to be 1 ½ in. Find the inside diameter. Answer: A A. 1.322 in B. 2.132 in C. 1.653 in D. 3.123 in
56. A ¼ in diameter shaft is designed with a working stress of 7000 psi in shear. If it rotates at 1725 rpm and shear modulus of elasticity is 12,000,000 psi, what is the torsional deflection in degrees per foot of length? Answer: C A. 3.820 B. 2.560 C. 3.210 D. 4.230 57. A hollow shaft has an outside diameter of 4 in and an inside diameter of 3 in. Find the diameter of a solid shaft with equal strength in torsion. Answer: D A. 2.12 in B. 3.23 in C. 4.23 in D. 3.52 in 58. A ¼ in steel shaft transmits 30 in-lb of torque. The effective length of the shaft is 12 in; the modulus of elasticity in shear is 12,000,000 psi. Find the angular deflection in degrees. Answer: C A. 2.240 B. 1.230 C. 4.480 D. 6.340 59. A 1 ½ in Monel shaft is used in a torsional application. Based on operating speed of 100 rpm and safety factor of 12. How much horsepower can it transmit? Assume the shearing stress is ¾ of the ultimate tensile stress which is 100,000 psi. Answer: A A. 6.57 hp B. 3.45 hp C. 2.34 hp D. 5.23 hp
KEYS 1.
A 76.2 mm in diameter shafting of SAE 1040 grade, cold rolled, having a yield point of 50 ksi and with a ¾ x 5 inches key. Compute the minimum yield point in the key in order to transmit the torque of the shaft. The factor of safety to use is 2 and Sys = 0.50 Sy. Answer: D A. 39.120 ksi B. 42.130 ksi C. 279.20 ksi D. 47.120 ksi
2.
A keyed sprocket delivers a torque of 778.8 N.m thru the shaft of 54 mm OD. The key thickness is 1.5875 cm and the width is 1.11 cm. Compute the length of the same key. The permissible stress value of 60 Mpa for shear and 90 Mpa for tension. Answer: D A. 39.12 cm B. 4.82 cm C. 52.22 cm D. 4.32 cm
3.
A 76.2 mm in diameter shafting of SAE 1040 grade, cold rolled, having a yield point of 50 ksi and with a ¾ x ¾ x 5 inches key. Compute the minimum yield point in the key in order to transmit the torque of the shaft. The factor of safety to use is 2 and S ys = 0.50 Sy. Answer: D A. 47.52 ksi B. 47.25 ksi C. 47.12 ksi D. 47.21 ksi
4.
A keyed gears delivers a torque of 912.4 N-m thru its shaft of 63.5 mm outside diameter. If the key has a thickness of 15.875 mm and width of 11.1125, find the length of the key. Assume the permissible stress values of 61.2 Mpa for shear and tension at 99.8 Mpa. Answer: C A. 47.42 mm B. 39.72 mm C. 42.22 mm D. 46.92 mm
5.
A metric M4 x 15 square key is used with a 16 mm shaft. If the allowable shearing stress is 50 Mpa. How much torque can the assembly handle? The rotational speed of the shaft is 600 rpm. Answer: C A. 20 N-m B. 12 N-m C. 24 N-m D. 34 N-m
6.
A flat key is to be designed for 75 mm diameter shaft which will transmit 150 KW at 400 rpm. If allowable shearing stress is 200 Mpa and key width is 55 mm, determine the length of key. Answer: B A. 30.65 mm B. 31.83 mm C. 33.75 mm D. 32.85 mm
7.
A rectangular key is used in pulley to transmit 100 Kw at 1000 rpm on 50 mm shaft diameter. Determine the force required to remove the shaft from the hub if friction is 0.4. Answer: D A. 33.24 KN B. 36.85 KN C. 28.35 KN D. 30.55 KN
8.
A 7/16 in height x 3 in length flat key is keyed to a 2 inches diameter shaft. Determine the torque in the key if bearing stress allowable is 25 Ksi. Answer: A A. 16,406.25 in-lb B. 15,248.56 in-lb C. 17.42 in-lb D. 246.75 in-lb
9.
A rectangular key is used in pulley connected to a line shaft at 15 Kw and 600 rpm. If shearing of key is 230 Mpa, determine the force acting on key length if key width one-fourth of shaft diameter and key length is 1 inch. Answer: C
A. B. C. D.
43 KN 48 KN 45 KN 46 KN
10. A square key is to be used in 40 mm diameter shaft and that will developed a 2 KN-m torque. If bearing stress of the key is 400 Mpa, determine the cross sectional dimension of square key to be used if key length is 30 mm. Answer: D A. 324.80 mm2 B. 246.80 mm2 C. 446.80 mm2 D. 277.77 mm2 11. A 100 KN force is acting on a key that has a length of 4 times its height. If bearing stress of key is 400 Mpa, determine the height of key. Answer: B A. 10.54 mm B. 11.18 mm C. 12.65 mm D. 15.25 mm 12. A one meter pulley is fastened to a 100 mm shaft by means of 25 mm square key and 150 mm long. What force tangent to pulley rim will shear the key if shear stress is 200 Mpa? Answer: C A. 65 KN B. 70 KN C. 75 KN D. 80 KN 13. A 1.2 m pulley is fastened to a 120 mm shaft by means of a square key with 140 mm long. What force tangent to pulley rim will crush the key if bearing stress is 410 Mpa. Assume key and shaft are of the same material. Answer: C A. 160.42 KN B. 165.25 KN C. 180.42 KN D. 172.20 KN COUPLING 1.
A flanged bolt coupling has ten (10) steel 25.4 mm diameter bolts evenly tighten around a 415 mm bolt circle. Determine the torque capacity of the connection if the allowable shearing stress in the bolt is 50 MN/m2. Answer: B A. 59.95 KN.m B. 52.6 KN.m C. 46.15 KN.m D. 43.8 KN.m
2.
A flanged bolt coupling consists of eight 20 mm diameter steel bolts space evenly around a bolt circle 300 mm in diameter. If the coupling is subjected to a torque of 15.1 KN-m, determine the maximum shearing stress in the bolts? Answer: A A. 40 Mpa B. 38 Mpa C. 70 Mpa D. 29 Mpa
3.
A flanged coupling having 180 mm bolt circle and 19 mm thick uses 8 bolts, 16 mm diameter to connect two shaft. It is used to transmit 60 Kw at 180 rpm. Determine the factor of safety in bearing if yield point in compression is 448 Mpa. Answer: C A. 15.6 B. 18.5 C. 30.8 D. 25.4
4.
A turbine connected to generator by means of flanged coupling that has a bolt circle diameter of 500 mm. The generator output is 40 MW, 3600 rpm and 90% efficiency. If there are 16 bolts, determine the force acting on each bolt. Answer: B A. 26.41 KN B. 29.47 KN C. 35.62 KN D. 32.61 KN
5.
A 75 mm diameter shaft is transmitting 300 Kw at 600 rpm. A solid coupling has a 6 bolts each 18 mm in diameter. Find the required bolt circle diameter if shearing stress in bolts is 27.5 Mpa.. Answer: A A. 227.40 mm B. 233.60 mm C. 254.50 mm D. 272.60 mm
6.
The total force of 125 KN is required of flange coupling that has 5 bolts has also shearing stress of 30 Mpa for bolt. Determine the required diameter of bolt. Answer: D A. 62.54 KN B. 54.21 KN C. 45.62 KN D. 32.57 KN
7.
A flanged coupling with bolt circle diameter of 250 mm uses 8 bolts, 25 mm diameter. The torque transmitted is 15 KN-m and compressive stress of bolt is 15 Mpa. Determine the required flange thickness. Answer: D A. 25 mm B. 30 mm C. 35 mm D. 40 mm PRESSURE VESSEL
1.
Find the thickness of a metal needed in the semi-spherical end of cylindrical vessel 0.70 meter in diameter subjected to an internal pressure of 2.7 N/mm 2. The material is mild carbon steel and tensile stress is 69 N/mm. Answer: D A. 5.2 mm B. 6.02 mm C. 7.53 mm D. 6.84 mm
2.
A cylindrical tank with 10 inches inside diameter contains oxygen gas at 2500 psi. Calculate the required wall thickness in millimeter under stress of 28,000 psi. Answer: B A. 10.54 B. 11.34 C. 10.24 D. 12.44
3.
Determine the bursting pressure of steel with diameter of 10 inches and make of ¼ in thick plate. The joint efficiency is at 70% and the tensile strength is 60 ksi. Answer: D A. 4,020 psi B. 4,002 psi C. 2,400 psi D. 4,200 psi
4.
Determine the safe wall thickness of a 30 inches steel with internal pressure of 7.82 Mpa. The yield stress of material is at 275.48 Mpa. The factor of safety to use is 2.0. Answer: C A. ¾ in B. 23.4 cm C. 21.6 mm D. 5/8 in
5.
Determine the bursting steam pressure of a steel shell with a diameter of 10 inches and made of ¼ inch thick steel plate. The joint efficiency is at 70% and the tensile strength is 60 ksi. Answer: A A. 4,200 psi B. 10.5 psi C. 42.8 psi D. 8,500 psi
6.
Compute the safe wall thickness of a 76.2 cm diameter steel tank. The tank is subjected to 7.33 Mpa pressure and the steel material has yield stress of 215.4 Mpa. The factor of safety to use is 3.Answer: B A. 1 ½ in B. 3.89 cm C. 4.09 cm D. 3.69 cm
7.
A steel cylinder air receiver with 5 feet diameter and pressure load of 180 psi, design stress of 9500 psi maximum. The pressure vessel is to be provided with 1 ½” diameter drain valve installed at the bottom of the vessel and safety pressure relief valve installed either at the top most or at the side with prop-out rating of 200 psi. Assume a 100% weld joint efficiency. The lap welding tensile strength is 65,000 psi. Determine the bursting pressure of this air receiver. Answer: B A. 1154 psi B. 1354 psi C. 1454 psi D. 1254 psi
8.
Determine the thickness of a steel air receiver with 30 inches diameter and pressure load of 120 psi, design stress of 8000 psi. Answer: A A. 1/4 in B. 3/8 in C. 5/8 in D. 1/2 in
9.
A cylindrical tank with 10” inside diameter contains oxygen gas at 2500 psi. Calculate the required wall thickness in (mm) under stress of 28,000 psi. Answer: C A. 11.44 mm B. 10.6 mm C. 11.34 mm D. 10.3 mm
10. Determine the internal pressure of a cylindrical tank 500 mm internal diameter, 20 mm thick and 3 m long if stress is limited to 140 Mpa. Answer: C A. 10.06 Mpa B. 10.52 Mpa C. 11.20 Mpa D. 12.88 Mpa 11. A water tank 10 m x 12 m is completely filled with water. Determine the minimum thickness of the plate if stress is limited to 50 Mpa. Answer: A A. 11.77 mm B. 12.66 mm C. 13.55 mm D. 12.44 mm
12. A spherical shell of 1.8 m outside and 1.725 m inside diameter contains helium at a pressure of 10.4 Mpa. Compute the stress in the shell.. Answer: B A. 124.08 Mpa B. 119.06 Mpa C. 96.48 Mpa D. 88.46 Mpa 13. A 600 mm diameter spherical steel pressure vessel has a uniform 8 mm wall thickness and an internal gage pressure of 10 Mpa. If the ultimate stress of steel is 420 Mpa, determine the factor of safety with respect to tensile of failure. Answer: A A. 2.30 B. 1.89 C. 2.69 D. 1.48 14. Determine the largest internal pressure which maybe applied to a cylindrical tank 2 m in diameter and 15 mm wall thickness, if the ultimate stress of steel is 420 Mpa and a factor of safety of 4.5. Answer: A A. 1.4 Mpa
B. 2.6 Mpa C. 1.8 Mpa D. 2.2 Mpa 15. The cylinder of a hydraulic press is made up of thick walled cylinder having an inside diameter of 300 mm. It is subjected to an internal pressure of 40 Mpa. Determine the thickness of a cylinder without exceeding a shearing stress of 80 Mpa. Answer: C A. 62.13 mm B. 58.61 mm C. 109.80 mm D. 72.40 mm 16. The internal pressure of a 400 mm internal diameter cylindrical tank is 10 Mpa and tank thickness is 25 mm. Determine the stress developed if joint efficiency is 95%. Answer: B A. 80.10 Mpa B. 84.21 Mpa C. 86.75 Mpa D. 78.42 Mpa 17. A spherical tank 15 mm thick has an internal pressure of 5 Mpa. The joint efficiency is 96% and stress is limited to 46,875 Kpa. Find the tank internal radius. Answer: C A. 540 mm B. 200 mm C. 270 mm D. 300 mm 18. A cylindrical tank has an inside diameter of 5 in and is subjected to an internal pressure of 500 psi. If maximum stress is 1200 pasi, determine the required thickness. Answer: C A. 1 in B. 1.2 in C. 1.4 in D. 1.6 in 19. A thick wall cylinder has 50 mm thick and internal diameter of 300 mm. If stress is limited to 30 Mpa, determine the maximum internal pressure. Answer: D A. 8.1 Mpa B. 8.2 Mpa C. 8.3 Mpa D. 8.4 Mpa 20. A round vertical steel tank has inside diameter of 3 m and 6 m height. It contains gasoline with a density of 750 Kg/m3. If the allowable tensile stress is 25 Mpa, find the minimum thickness required. Answer: A A. 2.65 mm B. 2.85 mm C. 3.65 mm D. 1.82 mm 21. A cylinder having an internal diameter of 16 in and external diameter of 26 inches is subjected to 1500 psi external pressure and internal pressure of 9,000 psi. Determine the hoop stress on outer surface of cylinder. Answer: B A. 8,742.65 psi
B. 7,642.85 psi C. 9,400.62 psi D. 9,471.43 psi 22. A cylindrical tank has a mean diameter of 40 cm and thickness of 10 cm. It is subjected to an external pressure of 140 kg/cm2. Determine the maximum internal tangential stress is 900 kg/cm 2. Determine the maximum internal pressure of the tank. Answer: A A. 2947.5 kg/cm2 B. 3426.5 kg/cm2 C. 1246.5 kg/cm2 D. 1942.6 kg/cm2 BOLTS & POWER SCREW 1.
2.
3.
4.
5.
6.
Compute the working strength of 1 in bolt is screwed up tightly in packaged joint when the allowable stress is 13,000 psi. Answer: D A. 3,600 lbs B. 3,700 lbs C. 3,800 lbs D. 3,900 lbs What is the working strength of a 2inches bolt which is screwed up tightly in a packed joint when the allowable working stress is 12,000 psi. Answer: A A. 20.4 klb B. 22.4 klb C. 23.4 klb D. 18 klb
An eyebolt is lifting a block weighing 350 lbs. The eyebolt is of SAE C 1040 material with S U = 67 ksi and SY = 55 ksi, what is the stress area ( in inches square ) of the bolt if it is under the unified coarse series thread? Answer: B A. 0.1341 B. 0.1134 C. 0.0991 D. 0.1043 If the pitch of a screw is 2/9 find the thread per inch. Answer: B A. 0.34 B. 4.5 C. 5.4 D. 17 Find the horsepower lost when a collar is loaded with 1000 lb rotates at 25 rpm, and has a coefficient of friction 0.15. The outside diameter of the collar is 4 in and the inside diameter is 2 in. Answer: C A. 0.045 hp B. 0.89 hp C. 0.089 hp D. 0.56 hp Compute how many 3/8 inch diameter set screws required to transmit 3 HP at a shaft speed of 1000 rpm. The shaft diameter is 1 inch. Answer: B
A. B. C. D.
1 1/2 2 3 1
7.
What is the frictional Hp acting on a collar loaded with 100 kg weight? The collar has an outside diameter of 100 mm amd an internal diameter of 40 mm. The collar rotates at 1000 rpm and the coefficient of friction between the collar and the pivot surface is 0.15. Answer: A A. 0.8 Hp B. 0.3 Hp C. 0.5 Hp D. 1.2 Hp
8.
Determine the permissible working stress of a UNC bolts that has a stress area of 0.606 in 2 if material used is carbon steel. Answer: A A. 4055.5 psi B. 5244.5 psi C. 4675.5 psi D. 4185.5 psi
9.
The stress area of NC bolt is 0.763 in 2, if material used is carbon steel, determine the applied load on the bolt. Answer: A A. 3407.14 psi B. 5244.5 psi C. 4675.5 psi D. 4186.5 psi
10. A 12 cm x 16 cm air compressor has 5 bolts on cylinder head with yield stress of 440 Mpa. If the bolt stress area is 0.13 in2, determine the maximum pressure inside the cylinder. Answer: B A. 546.71 psi B. 671.96 psi C. 742.78 psi D. 840.60 psi 11. The cylinder head of ammonia compressor has core gasket area of 80 cm 2 and flanged pressure of 90 kg/cm2. Determine the torque applied on the bolt if nominal diameter of bolt used is ¾ inch and there 5 bolts. Answer: A A. 476.28 in-lbs B. 586.28 in-lbs C. 696.28 in-lbs D. 666.26 in-lbs 12. The total torque required to turn the power screw is 50 N-m. If linear speed of screw is 8 ft/min and lead of 8 mm, determine the Hp input of the power screw. Answer: C A. 2.82 Hp B. 2.54 Hp C. 2.14 Hp D. 2.38 Hp
13. A single square thread power screw has a lead of 6 mm and mean diameter of 34 mm. It is used to lift a load of 26 KN and coefficient of friction of thread is 0.15, determine the torque required to turn the screw. Answer: A A. 91.9 N-m B. 65.8 N-m C. 72.6 N-m D. 86.5 N-m 14. An ACME thread power screw that has a mean diameter of 25 mm and a pitch of 5 mm is used to lift a load of 500 kg. If friction on threads is 0.1, determine the torque needed to turn the screw. Answer: A A. 10.30 N-m B. 12.63 N-m C. 13.10 N-m D. 14.10 N-m 15. The torque required to overcome collar friction of a 100 mm mean diameter collar power screw is 50 N-m and collar friction of 0.15. Determine the weight lifted by the screw. Answer: D A. 458.57 kg B. 478.57 kg C. 487.57 kg D. 679.57 kg
16. A double square thread power screw has a mean radius of 80 mm and a pitch of 10 mm is used to lift a load of 80 KN. If friction of screw is 0.13 and collar torque is 20% of input torque, determine the input torque required. Answer: D A. 830.76 N-m B. 835.76 N-m C. 1246.30 N-m D. 1365.30 N-m 17. The root diameter of a double square thread power screw is 0.55 in. The screw has a pitch of 0.2. Determine the major diameter. Answer: B A. 0.524 in B. 0.750 in C. 0.842 in D. 0.961 in 18. A power screw consumes 6 Hp in raising a 2800 lb weight at the rate of 30 ft/min. Determine the efficiency of the screw. Answer: C A. 12.5% B. 16.8% C. 42.42% D. 66.62% 19. A square thread power screw has a pitch diameter of 1.5” and a lead of 1”. Neglecting collar friction, determine the coefficient of friction for threads if screw efficiency is 63.62%. Answer: A
A. B. C. D.
0.113 0.121 0.146 0.151
20. A square thread screw has an efficiency of 70% when friction of threads is 0.10 and collar friction is negligible. Answer: A A. 14.300 B. 10.370 C. 12.430 D. 16.450 FLYWHEEL 1.
A cast iron flywheel is rotated at a speed of 1200 rpm and having a mean radius of 1 foot. If the weight of the rim is 30 lbs, what is the centrifugal force? Use factor C = 41. Answer: D A. 14,800 lbs B. 14,860 lbs C. 7 mt D. 14,724 lbs
2.
A flywheel for a punching press must be capable of furnishing 3400 N-m of energy during the 25% revolution while the hole is being punched. The flywheel maximum speed is 200 rpm and the speed decreases 8.7% during the load stroke. The mean radius of the rim is 1016 mm diameter and contributes 90% of the energy requirements. Approximate total weight of the flywheel to be 1.20 times that of the rim. Find the weight of the flywheel. Answer: A A. 97.5 kg B. 65.2 kg C. 103.34 kg D. 234.5 kg
3.
A press is used to punch 10 holes per minute of 30 mm diameter hole from 25 mm thick plate. Determine the power needed to punch a hole if ultimate shear stress is 400 Mpa. Answer: B A. 2.68 Kw B. 1.96 Kw C. 3.58 Kw D. 0.96 Kw
4.
The kinetic energy needed to punch a hole is 5 KJ. What is the maximum thickness of a hole that can be punch if hole diameter is 25 mm and ultimate shearing stress of plate is 420 Mpa. Answer: C A. 12.61 mm B. 14.68 mm C. 17.41 mm D. 19.62 mm
5.
During a punching process of 350 kg flywheel the speed varies from 200 rpm to 180 rpm with 1 m mean diameter. Determine the kinetic energy released by the flywheel. Answer: A A. 3.64 KJ B. 6.28 KJ C. 4.51 KJ D. 5.62 KJ
6.
A plate 200 mm wide and 25 mm thick with strength of 410 Mpa is to be shear along its width. During shearing process an 800 mm mean diameter flywheel changes its speed from 200 rpm to 180 rpm. Determine the weight of flywheel to be use. Answer: D A. 3265.84 kg B. 3452.71 kg C. 3821.72 kg D. 3845.97 kg
7.
The energy required to punch a square hole from 20 mm thick plate is 10 KJ. If the ultimate strength of plate is 420 Mpa, determine the maximum sides of square that can be punched. Answer: B A. 45 mm B. 30 mm C. 60 mm D. 55 mm
8.
A 1 mm mean diameter flywheel, 500 kg weight changes its speed from 220 rpm to 200 rpm during shearing process. What average force is needed to shear a 30 mm thick plate. Answer: A A. 384 KN B. 653 KN C. 234 KN D. 1082 KN
9.
The energy required to punch a hole is 3 KJ from a flywheel mean diameter of 800 mm that slows down from 3.3 rps to 3 rps during punching. If weight of arm and hub account 10% of rim weight, determine the rim weight. Answer: B A. 421.08 kg B. 457.40 kg C. 482.68 kg D. 416.68 kg
10. A flywheel has a total weight of 500 kg and the weight of arm and hub is 8% of total weight. It has a mean diameter of 1 m and width of 300 mm. Determine the thickness of the flywheel if density of material is 7000 kg/m3. Answer: C A. 60.65 mm B. 65.48 mm C. 69.72 mm D. 75.42 mm 11. A flywheel has a rim weight of 450 kg and mean radius of 450 mm. If the rim width is 5 times the rim thickness and material density is 7200 kg/m3, determine the width of flywheel. Answer: A
A. B. C. D.
332.45 mm 242.61 mm 286.76 mm 298.78 mm
12. The power required to shear a plate 50 mm thick for 10 seconds is 5 Kw. If ultimate strength of plate is 420 Mpa. How wide should the plate be? Answer: D A. 80.42 mm B. 85.65 mm C. 90.28 mm D. 95.23 mm 13. A 900 mm mean diameter flywheel has a width of 350 mm, 75 mm thick and density of 7100 kg/m 3. Neglecting the weight of arm and hub, find the energy released if its speed changes from 280 rpm to 250 rpm. Answer: B A. 7.89 KJ B. 9.30 KJ C. 5.48 KJ D. 6.71 KJ 14. A flywheel weighing 1000 kg has a radius of gyration of 1.5 m. The normal operating speed is 160 rpm and coefficient of fluctuation is 0.08, determine the energy released by the flywheel. Answer: D A. 31.70 KJ B. 36.70 KJ C. 41.70 KJ D. 46.70 KJ 15. A 5 ft mean diameter flywheel has to absorb 3500 ft-lb of energy and maintain a coefficient of fluctuation of 0.09. If mean speed is 80 ft/sec, find the weight of flywheel. Answer: B A. 190.66 lbs B. 195.66 lbs C. 198.66 lbs D. 200.77 lbs SPRING 1.
A body weighing 1000 lbs falls from a height of 6 in and strikes a 2000 lb/in spring. The deformation of the spring is_______. Answer: C A. 2 B. 4 C. 3 D. 5
2.
Compute the deflection of an 18 coils helical spring having a load of 100 kg. The modulus of elasticity in shear of spring is 96.62 Gpa, OD of 9.256 cm and with wire diameter of 9.525 mm. The spring is squared and ground ends. Answer: A A. 9 cm B. 101 cm C. 11 cm D. 14 cm
3.
Compute the maximum deflection of a 20 coils helical spring having a load of 75 kgs. The spring is a square/ground ends with modulus of elasticity in shear of 79.84 Gpa, outside diameter of 101.6 mm, wire diameter of 9.525 mm. Answer: D A. 140.7 mm B. 112.7 mm C. 15.17 mm D. 126.7 mm
4.
A three extension coil springs are hooked in series that support a single weight of 100 kg. The first spring is rated at 0.400 kg/mm and the other 2 lower springs is rated at 0.64 kg/mm. Compute the total deflection. Answer: A A. 563 mm B. 268 mm C. 156 mm D. 250 mm
5.
A high alloy spring having squared and ground ends and has a total of 16 coils and modulus of elasticity in shear of 85 Gpa. Compute the Wahl factor. The spring outside diameter is 9.66 cm wire diameter is 0.65 cm. Answer: C A. 1.058 B. 1.185 C. 1.10 D. 1.2
6.
A coil spring with 5 cm outside diameter is required to work under the load of 190 N. The wire diameter is 5 mm, the spring is to have 6 active coils and the ends are to be closed and ground. Determine the total number of coils. The modulus of rigidity is 80 Gpa, and the mean radius is to be 23 mm, with 7 mm pitch of the spring. Answer: B A. 6.5 coils B. 8.5 coils C. 7.5 coils D. 9.5 coils
7.
A helical spring having square and ground ends a total of 18 coils and its material has modulus of elasticity in shear of 78.910 Gpa. If spring has an outside diameter of 10.42 cm and wire diameter of 0.625 cm, compute the maximum deflection that can be produced in the spring due to a load of 50 kgs. Answer: B A. 302 mm B. 490 mm C. 342 mm D. 322 mm
8.
An extension coil spring is to be elongated 5 in under a load of 50 lb. What is the spring rate? Answer: B A. 5 lb/min B. 10 lb/min C. 15 lb/min D. 20 lb/min
9.
A spring has a rate of 50 lb with a spring index of 8. If stress induced is 90,000 psi, determine the wire diameter. Answer: D A. 0.058 in B. 0.828 in C. 0.452 in D. 0.1157 in
10. Determine the maximum shearing stress of a helical spring composed of 20 turns of 20 mm diameter wire on a mean radius of 80 mm when the spring is supporting a load of 2 KN. G = 83,000 Gpa. Answer: C A. 108.20 Mpa B. 98.62 Mpa C. 120.60 Mpa D. 88.68 Mpa 11. A helical spring is made by wrapping steel wire 20 mm diameter around a forming cylinder 150 mm in diameter. Compute the elongation of the spring without exceeding a shearing stress of 140 Mpa if it is composed of 18 turns. Answer: C A. 96.42 mm B. 100.6 mm C. 117.57 mm D. 89.62 mm
12. It is found that a load of 50 lbs on extension coil spring deflects 8.5 in. What load will the spring deflects 2.5 in? Answer: D A. 10.64 lb B. 12.48 lb C. 13.48 lb D. 14.70 lb 13. A spring sustain 200 ft-lb of energy with deflection of 3 in. Assume that the coil diameter is 7 times the wire diameter and allowable stress of 100,000 psi, determine the wire diameter. Answer: A A. 0.416 in B. 0.321 in C. 0.568 in D. 0.672 in 14. A weight of 100 lbs strikes a coil from a height of 18 inches and deflects the spring of 6 inches. Find the average force acting on the spring. Answer: C A. 600 lb B. 700 lb C. 800 lb D. 900 lb 15. Three coil spring are hooked in series and support a weight of 70 kg. One spring has a spring rate of 0.209 kg/min and the other two have spring rates of 0.643 kg.mm. Find the deflection. Answer: C A. 346.71 mm
B. 389.30 mm C. 552.65 mm D. 416.58 mm 16. Four compression coil spring in parallel support a load of 360 kg. Each spring has a gradient of 0.717 kg/mm. Find the deflection. Answer: A A. 125.52 mm B. 132.52 mm C. 138.52 mm D. 145.52 mm 17. A force of 1.1 KN is acting on a 7.5 active coils with wire diameter of 13 mm. The outside diameter of coil is 117 mm and G = 80 GN/m2. Find the coil deflection. Answer: C A. 27.60 mm B. 29.80 mm C. 32.50 mm D. 34.60 mm 18. A concentric helical spring is use to support a load of 90 KN. The inner spring has a rate of 495.8 KN/m and outside spring is 126.5 KN/m. If initially the inner spring is 25 mm shorter than the outer spring, find the percent load carried by inner spring. Answer: D A. 34.56% B. 55.86% C. 68.25% D. 76.81% 19. How long a wire is needed to make helical spring having a mean diameter of 1 inch if there are 8 active coils? Answer: A A. 25.13 in B. 26.65 in C. 30.21 in D. 32.34 in 20. A 0.08” diameter spring has a length of 20 in. If density of spring is 0.282 lb/in 3, determine the mass of spring. Answer: B A. 0.0395 lb B. 0.0283 lb C. 0.0485 lb D. 0.0686 lb 21. A square and ground ends spring has a free length of 250 mm. There are 10 active coils with wire diameter of 12.5 mm. If the spring rate is 150 KN/m and mean diameter is 100 mm, determine the solid stress. Answer: A A. 2,315.54 Mpa B. 7,654.8 Mpa C. 7,842.7 Mpa D. 8,432.9 Mpa
22. A square and ground ends spring has a pitch of 20 mm, wire diameter of 12.5 mm. If there are 12 actual number of coils, find the deflection when the spring is compressed to its solid strength. Answer: B A. 78 mm B. 75 mm C. 77 mm D. 79 mm 23. A spring with plain ends has 15 active coils, diameter of 6 mm and pitch of 10 mm. If spring rate is 100 KN/m, determine the solid force. Answer: C A. 4 KN B. 5 KN C. 6 KN D. 7 KN 24. A spring has a spring rate of 30 KN/m. If wire diameter is 10 mm with mean diameter of 70 mm, determine the number of active coils. G = 80 GN/m2. Answer: D A. 6.54 B. 7.82 C. 8.42 D. 9.72 25. A spring has a diameter of 25 mm and 12 active coils. If a load of 10 KN is applied it deflects 75 mm. Determine the mean diameter of the spring if G = 80 GN/m2. Answer: C A. 124.65 mm B. 129.65 mm C. 134.65 mm D. 140.65 mm GEAR 1.
Compute the tooth thickness of 14 ½ deg. spur gear with diameter pitch of 5. Answer: A A. 0.34116 in B. 0.31146 in C. 0.41416 in D. 0.31461 in
2.
A 36 tooth pinion with a turning speed of 300 rpm drives 120 tooth gear of 14 ½ degrees involute full depth pressure angle. What would be the speed of the driven gear. Answer: C A. 1000 rpm B. 100 rpm C. 90 rpm D. 140 rpm
3.
A triple thread worm has a pitch diameter of 3 inches. The wheel has a 25 teeth and a pitch diameter of 5 inches. Material for both the worm and the wheel is of phosphor bronze. Compute the helix angle (tan α). Answer: A A. 0.20 B. 0.30 C. 0.40 D. 14
4.
Find the tooth thickness on tooth circle of a 20 degree full depth involute tooth having a diametrical pitch of 3, circular pitch of 1.0472 and whole depth of tooth at 0.60. Answer: B A. 10.7 mm B. 13.2 mm C. 10.1 mm D. 7.9 mm
5.
A pair of gear/pinion of 42 tooth and 18 tooth with a diametrical pitch of 0.7874 teeth/cm and the addendum is 0.80/p and the addendum 1/p. The gear pressure angle is 20 0. Compute the center distance of the pair of gears in meters. Answer: C A. 0.5026 m B. 0.3426 m C. 0.381 m D. 0.4013 m
6.
A helical gear having a 14 1/20 normal pressure angle and transverse diametrical pitch of 2.3622 per cm. The helix angle is at 450 and has 8 teeth. Compute the transverse pressure angle in degrees. Answer: D A. 22.20 B. 18.90 C. 19.30 D. 20.10
7.
Two idlers of 28T and 26T are introduced between the 24T pinion with a turning speed of 400 rpm driving a final 96T gear. What would be the final speed of the driven gear and its direction relative to the driving gear rotation? Answer: C A. 120 rpm and opposite direction B. 80 rpm and same direction C. 100 rpm and opposite direction D. 100 rpm and same direction
8.
A spur pinion rotates at 1800 rpm and transmits to a mating gear 30 HP. The pitch diameter is 4” and the pressure angle is 14 1/2. Determine the tangential load in lbs. Answer: C A. 495 B. 535 C. 525 D. 475
9.
Compute the pitch angle of a bevel gear given the pinion’s number of teeth of 14 and 42 teeth on the gear. Answer: A A. 18.40 B. 33.40 C. 28.40 D. 38.40
10. Compute the circular pitch of a pair of gears having a ratio of 4 and a center distance of 10.23. Each gear has 72 teeth and pinion has 18 teeth. Answer: C A. 0.8095 B. 0.8035 C. 0.7854 D. 0.8085 11. The tooth thickness of a gear is 0.5 inch and its circular pitch is 1.0 inch. Calculate the dedendum of the gear. Answer: B A. 0.3183 B. 0.3979 C. 1.250 D. 0.1114 12. An internal gear is set up with a 5 in diameter pinion and center distance of 18 inches. Find the diameter of the internal gear. Answer: D A. 36” B. 21.5” C. 26” D. 41” 13. The minimum whole depth of spur gear of 14-1/2 deg. involute type with diameter pitch of 24 and circular pitch of 0.1309. Answer: C A. 0.09000 B. 0.08900 C. 0.08987 D. 0.08975 14. The minimum clearance allowed for meshing spur gears with a circular pitch of 0.1571 and diametrical pitch of 20. The spur gear have 25 teeth. Answer: A A. 0.007855 B. 0.007558 C. 0.008578 D. 0.007585 15. Find the distance between centers of a pair of gears, one of which has 12 teeth and the other 37 teeth. The diametrical pitch is 7. Answer: B A. 3 in B. 3.5 in C. 4 in D. 4.5 in 16. Determine the pitch diameter of a gear with 28 teeth, 4 diametrical pitch. Answer: A A. 7 in B. 8 in C. 9 in D. 10 in 17. Two parallel shafts have an angular velocity ratio of 3 to 1 are connected by gears, the largest of which has 36 teeth. Find the number of teeth of smaller gear. Answer: C
A. B. C. D.
10 11 12 13
18. The parallel shafts have a center distance of 15 in. One of the shaft carries a 40-tooth, 2 diametrical pitch gear which drives a gear on the other shaft at a speed of 150 rpm. How fast is the 40-tooth turning? Answer: D A. 600 rpm B. 300 rpm C. 150 rpm D. 75 rpm 19. A pair of meshing gears has a diametrical pitch of 10, a center distance of 2.6 inches, and velocity ratio of 1.6. Determine the number of teeth of smaller gear. Answer: B A. 10 B. 20 C. 30 D. 40 20. A spur gear 20 degrees full-depth involute teeth has an outside diameter of 195 mm and a module of 6.5. Determine the number of teeth. Answer: C A. 20 B. 25 C. 28 D. 41
21. What is the pitch diameter of a 40-tooth gear having a circular pitch of 1.5708 in? Answer: A A. 20 in B. 25 in C. 30 in D. 35 in 22. How many revolutions per minute is a spur gear turning if it has 28 teeth, a circular pitch of 0.7854 in and a pitch line velocity of 12 ft/sec? Answer: D A. 378.44 rpm B. 643.82 rpm C. 954.66 rpm D. 392.88 rpm 23. How many revolutions per minute is a spur gear turning if it has a module of 2, 40 teeth, and a pitch line velocity of 2500 mm/sec? Answer: A A. 596.83 rpm B. 386.83 rpm C. 476.85 rpm D. 312.83 rpm 24. The module of a gear having a diametrical pitch of 8 is: Answer: B A. 5.234
B. 3.175 C. 4.23 D. 2.34 25. The diametrical pitch of a gear having a module of 2.3 is: Answer: B A. 9 B. 11 C. 10 D. 12 26. A gear turning 300 rpm has diametrical pitch of 8. If there are 40 teeth on the gear, find the pitch line velocity of gear. Answer: A A. 6.54 fps B. 8.34 fps C. 7.45 fps D. 9.45 fps 27. Two gears meshing each other have 18 teeth and 30 teeth. If circular pitch is 0.23 in. Find the center distance between gears. Answer: D A. 5.23 in B. 2.34 in C. 3.23 in D. 1.76 in
28. A gear with pitch line velocity of 6.126 m/s when turning at 600 rpm. If module is 3, find the number of teeth on the gear. Answer: C A. 60 B. 50 C. 65 D. 70 29. Two gears meshing each other has a center distance of 200 mm. The pinion has 20 teeth and gear has 60 teeth. Find the module of meshing gears. Answer: D A. 2 B. 4 C. 3 D. 5 30. A gear has a tooth thickness of 0.1308 in. Find the addendum of the gear at 14.5 0 involute. Answer: A A. 2.12 mm B. 4.12 mm C. 3.12 mm D. 5.12 mm 31. A gear has an addendum of 0.10 in. What is the dedendum of the gear at 20 0 pressure involute. Answer: B
A. B. C. D.
0.037 in 0.125 in 0.345 in 0.235 in
32. A gear is use to transmit 12 Kw at 450 rpm with 26 teeth. If the diameter pitch of the gear is 10, find the force tangent to the gear. Answer: C A. 12.34 KN B. 14.24 KN C. 15.42 KN D. 16.45 KN 33. A gear is use to transmit 20 Kw at 600 rpm to a driven gear. The pinion has a pitch diameter of 200 mm. If pressure angle is 14.5 degrees, find the load that tends to separate the two gears. Answer: D A. 0.234 KN B. 0.534 KN C. 0.763 KN D. 0.823 KN 34. The pressure angle of the 12 in diameter gear is 20 degrees. The total load of the gear is 5 KN and is turning at 750 rpm. Find the power delivered by the gear. Answer: C A. 43.23 KN B. 64.23 KN C. 56.23 KN D. 34.23 KN
35. Three gears meshing each other has a driving power of 30 Kw with 900 rpm. The speed ratio is 1:3:5 and each meshing gear has an efficiency of 96%. Find the torque developed of the driven gear, KN.m. Answer: A A. 4.40 B. 7.60 C. 5.60 D. 8.20 BEARING 1.
A 1 inch horizontal shaft rotates at 500 rpm in a sleeve-type bearing. The coefficient of friction is 0.15. Calculate the horsepower lost in the bearing if the reaction between the shaft and the bearing is 800 lb. Answer: D A. 0.2634 hp B. 1.2344 hp C. 0.0925 hp D. 0.4759 hp
2.
A 2 in horizontal shaft rotates in a sleeve type bearing. The coefficient of friction is 0.10 and the shaft applies a load of 500 lb. Find the frictional resistance. Answer: D A. 20 lbs B. 40 lbs C. 30 lbs
D. 50 lbs 3.
A bearing sustains a load of 4450 N. The shaft diameter is 100 mm, the coefficient of sliding friction is 0.01, and the shaft speed is 400 rpm. Find the horsepower lost in the bearing. Answer: A A. 93.20 watts B. 76.34 watts C. 83.45 watts D. 45.23 watts
4.
A 50 mm diameter shaft supported by two sleeve bearings carries a load of 13.3 MN. The shaft rotates at 150 rpm. If the coefficient of sliding friction between the shaft and bearings is 0.1, how much power is lost in friction? Answer: A A. 261 kw B. 643 kw C. 345 kw D. 108 kw
5.
A 36 mm shaft uses a sleeve bearing that sustain a load of 4000 N. If the allowable bearing pressure is 1.3 MN/m2. Find the length of the bearing. Answer: D A. 75.47 mm B. 23.44 mm C. 89.23 mm D. 85.47 mm
6.
A 20 mm shaft uses sleeve bearings. The total load per bearing is 2000 N. An L/D ratio of 2.5 is desired. What is the bearing pressure? Answer: C A. 1 Mpa B. 3 Mpa C. 2 Mpa D. 4 Mpa
7.
A 22 mm diameter shaft is supported by sleeve bearing at a distance of 0.50 m. A load of 2.2 KN is applied at 0.2 m from the left end. The sleeve bearings have an L/D ratio of 1.5. Find the maximum bearing pressure. Answer: A A. 1.82 Mpa B. 3.45 Mpa C. 2.12 Mpa D. 5.23 Mpa
8.
A sleeve bearing is to have an LD ratio of 1.0 and an allowable bearing pressure of 0.5 MN/m 2. Find the inside diameter and the length of the bearing if it is to sustain a load of 2550 N. Answer: B A. 23.45 mm B. 71.41 mm C. 45.34 mm D. 98.34 mm
9.
A sleeve bearing has an outside diameter of 1.50 in and a length of 2 in. The wall thickness is 3/16 in. The bearing is subjected to a radial load of 450 lb. Find the bearing pressure. Answer: C A. 100 psi B. 150 psi C. 200 psi D. 250 psi
10. A thrust washer has an inside diameter of 12 mm and an outside diameter of 75 mm. If the allowable bearing pressure is 0.6 Mpa, how much load can it sustain? Answer: A A. 2582.9 N B. 1235.5 N C. 3293.44 N D. 8634.45 N BELTS 1.
Find the angle of contact on the small pulley for an open belt drive with a 72 in center distance. The pulley diameters are 6 in and 12 in. Answer: A A. 175.22° B. 170.34° C. 185. 34° D. 165.34°
2.
Find the belt length at a 72 in distance connected in open belt. The pulley diameters are 6 and 12 in. Answer: D A. 162.34 in B. 173.45 in C. 123.55 in D. 172.39 in A 6 in diameter pulley turning at 600 rpm is belt connected to ma 12 in diameter pulley. If there is 4% slip, find the speed of the 12 in pulley. Answer: D A. 187 rpm B. 223 rpm C. 203 rpm D. 288 rpm
3.
4.
For a given belt a manufacturer gives a horsepower rating of 2.5 hp per inch of width based on a belt speed of 2600 ft/min. The drive is to handle 10 hp and the arc of contact correction factor is 0.90. Find the width of belt needed. Assume that the belt widths are available in 1 inch increments. Answer: B A. 3 in B. 5 in C. 4 in D. 6 in
5.
A ¼ in round endless belt connects a 1 in diameter pulley with a 2 in pulley; spacing between pulleys is 4 in on centers. The allowable stress is 400 psi. If the 1 in pulley is the driver and rotates 100 rpm. How much horsepower can be transmitted? Assume the coefficient of friction to be 0.30 for each pulley. Answer: D A. 0.123 hp B. 1.234 hp
C. 0.0115 hp D. 0.0090 hp 6.
A 3/8 in flat leather belt is 12 in wide and is used on a 24 in diameter pulley rotating 600 rpm. The specific weight of the belt is 0.035 lb/in 3. The angle of contact is 150°. If the coefficient of friction is 0.3 and the allowable stress is 300 psi how much hp can it transmit? Answer: B A. 34.5 hp B. 69.5 hp C. 78.5 hp D. 54.5 hp
7.
A 5 mm round belt connects a 20 mm pulley with a 40 mm pulley. The center distance is 150 mm. The 20 mm pulley rotates at 100 rpm and the coefficient of friction of the belt is 0.25. Find the horsepower capacity for this arrangement if the allowable belt stress is 2.6 N/mm 2. Answer: C A. 0.12 kw B. 0.23 kw C. 0.00282 kw D. 0.054 kw BRAKE
1.
The band brake of a band brake has 210 degrees of contact with its drum. By laboratory tests, it is found that the pull on the tight side is 800 lbs and the pull on the slack side is 285 lb. What is the coefficient of friction? Answer: A A. 0.281 B. 0.753 C. 0.186 D. 0.453
2.
The inertia load on an electric brake is 32 lb-ft 2 and the drive shaft is rotating at 2000 rpm. What average torque is required to bring this load to a complete stop in 1.2 sec? Answer: A A. 173.61 ft-lbs B. 153.45 ft-lbs C. 123.45 ft-lbs D. 237.23 ft-lbs
3.
The band of a band brake has a contact angle of 180°. It is found experimentally that the pulls on the bands are 275 kg and 100 kg respectively under certain operating conditions. Find the coefficient of friction. Answer: D A. 0.973 B. 0.567 C. 0.197 D. 0.322
4.
A brake requires 900 in-lb of torque to stop a shaft operating at 840 rpm in a period of 3.5 seconds. What is the inertial load expressed in lb-ft 2? Answer: D A. 90.23 B. 74.34 C. 34.45 D. 96.25
CLUTCH 1.
A cone clutch has an angle of 10° and coefficient of friction of 0.42. Find the axial force required if the capacity of the clutch is 7 kw at 500 rpm. The mean diameter of the active conical sections is 300 mm. Answer: C A. 234.45 N B. 186.45 N C. 368.49 N D. 492.45 N
2.
How much torque can a cone clutch transmit if the angle of the conical elements is 10 degrees the mean diameter of the conical clutch sections 200 mm and an axial force of 550 N is applied? Assume the coefficient of friction is 0.45. Answer: C A. 123.23 N-m B. 34.56 N-m C. 142.53 N-m D. 234. 56 N-m
3.
If the inertia is 90 lb-ft 2 and the speed of the driven shaft is to be increased from 0 to 2500 rpm in 5 seconds, shaft material is of SAE 4140 with yield strength of 110,000 lb/in 2, find the clutch starting torque in ft-lb. Answer: C A. 159 B. 128 C. 146 D. 191
4.
Find the frictional radius for a disc clutch. The disc clutch has an outside diameter of 10 in and an inside diameter of 6 in. Answer: B A. 4.54 in B. 4.08 in C. 5.34 in D. 8.44 in
5.
In a clutch the outside diameter is 8 in and the inside diameter is 4 in. An axial force of 400 lb is used to hold the two parts together. If the coefficient of friction of the mating materials is 0.4, how much torque can the clutch handle? Answer: B A. 123.45 in-lb B. 497.80 in-lb C. 213.34 in-lb D. 563.23 in-lb
6.
A disc clutch has 6 pairs of contracting friction surfaces. The frictional radius is 2 in and the coefficient of friction is 0.3. An axial force of 100 lbs acts on the clutch. The shaft speed is 400 rpm. How much horsepower can the clutch transmit? Answer: A A. 2.28 hp B. 1.23 hp C. 3.23 hp
D. 4.23 hp 7.
A cone clutch has cone elements at an angle of 10°. The clutch transmits 20 hp at a speed of 100 rpm. The mean diameter of the conical friction sections is 16 in and the coefficient of friction is 0.3. Find the axial force needed to engage the clutch. Answer: A A. 246.37 lbs B. 212.56 lbs C. 234.56 lbs D. 346.78 lbs
8.
In a band clutch, the ratio of the pull on the tight side of the band to that of the slack side is 4:1. The band contacts the drum for 250 degrees. What is the coefficient of friction? Answer: B A. 0.123 B. 0.318 C. 0.234 D. 0.462
9.
A band clutch has an angle of contact of 270° on a 15 in diameter drum. The rotational speed of the drum is 250 rpm and the clutch transmits 8 hp. The band is 1/16 in thick and has a design stress of 5000 psi. How wide should the band be? Assume a coefficient of friction of 0.40. Answer: C A. 2.123 in B. 3.234 in C. 1.014 in D. 4.354 in
10. The angle of contact of a band clutch is 250 degrees. The cross section of the band is 1/16 in x 1.5 in. The design stress for the band material is 8,000 psi. If the drum is 16 inches in diameter and rotates at 350 rpm, what is the horsepower capacity of the clutch? The coefficient of friction is 0.4. Answer: D A. 20.34 hp B. 15.23 hp C. 22.34 hp D. 27.50 hp 11. Find the power capacity under uniform wear of a cone clutch with mean diameter of 250 mm if the conical elements are inclined 8 degrees and the axial force is 450 N. The rotational speed of the driver is 200 rpm and the coefficient of friction is 0.20. Answer: A A. 1.683 kw B. 2.340 kw C. 1.287 kw D. 3.234 kw 12. Determine the power capacity of a cone clutch under uniform pressure and assuming the following conditions: major diameter = 250 mm; minor diameter = 200 mm; length of conical elements in contact = 125 mm; rotational speed = 870 rpm; coefficient of friction = 0.30; and allowable pressure = 70,000 N/m2? Answer: B A. 12.34 kw
B. 19.09 kw C. 14.56 kw D. 23.45 kw 13. Find the power capacity under uniform wear of a cone clutch with the following specification speed = 870 rpm; length of conical elements in contact = 125 mm; major diameter = 250 mm; minor diameter = 200 mm; coefficient of friction = 0.30; and axial operating force = 500 N. Answer: A A. 7.69 kw B. 5.23 kw C. 9.34 kw D. 3.23 kw 14. Assuming uniform wear, find the power capacity of a single disc clutch with an outside and inside diameter of 200 mm and 100 mm respectively, rotational speed of 1160 rpm, a coefficient of friction of 0.35 and an axial operating force of 800 Newtons. Answer: B A. 4.23 kw B. 2.55 kw C. 6.32 kw D. 8.23 kw MACHINERIES 1.
2.
3.
4.
5.
A flywheel on a press rotating at 120 rpm is slowed to 102 rpm during a punching process that requires ¾ sec for the punching portion of the cycle. What angular deceleration the flywheel experience? Answer: A A. -2.52 rad/s2 B. -5.45 rad/s2 C. -1.23 rad/s2 D. -8.45 rad/s2 A 100 lb body is being hoisted by a winch, the tension in the hoisting cable being kept constant at 110 lb. At what rate the body is accelerated? Answer: B A. 1.22 ft/s2 B. 3.22 ft/s2 C. 2.22 ft/s2 D. 4.44 ft/s2 A body of mass 50 kg is being hoisted by a winch, and the tension in the cable is 600 N. What is the acceleration? Answer: D A. 4.23 m/s2 B. 5.23 m/s2 C. 3.23 m/s2 D. 2.19 m/s2 A flywheel has a diameter of 3 ft and weighs 1000 pounds. What torque must be applied, neglecting bearing friction, to accelerate the flywheel at the rate of 100 revolutions per minute, per second? Answer: C A. 265.8 ft-lbs B. 565.80 ft-lbs C. 365.80 ft-lbs D. 665.80 ft-lbs A flywheel has a diameter of 1.5m, and a mass of 800 kg. What torque is needed to produce an angular acceleration of 100 revolutions per minute, per second? Answer: D A. 5356 N.m
6.
7.
8.
B. 4356 N.m C. 3356 N.m D. 2356 N.m A 12 inch cube of steel weighing 490 lbs is being moved on a horizontal conveyor belt at a speed of 6 miles per hour (8.8 ft/s). What is the kinetic energy of the cube? Answer: B A. 323.45 ft-lbs B. 489.22 ft-lbs C. 534.34 ft-lbs D. 633.34 ft-lbs If a cube of mass 200 kg is being moved on a conveyor belt at a speed of 3 m/s, what is the kinetic energy of the cube? Answer: D A. 800 J B. 900 J C. 850 J D. 950 J A pile driver weighing 200 pounds strikes the top of the pile after being fallen from a height of 20 ft. If forces a pile into the ground a distance of ½ foot. What is the average force of the blow? Answer: A A. 8,200 lbs B. 8,600 lbs C. 8,400 lbs D. 8,800 lbs
9.
A pile driver of mass 100 kilograms falls 10 meters and moves the pile a distance of 0.3 m. What is the average force of the blow? Answer: B A. 23.45 KN B. 33.68 KN C. 54.23 KN D. 43.23 KN 10. A 1000 lb block is pulled up a 2-degree incline by a cable exerting a constant force F of 600 lbs. If the coefficient of friction between the block and the plane is 0.5, how fast will the block be moving up the plane 10 seconds after the pull is applied? Answer: D A. 12.4 mph B. 10.2 mph C. 17.3 mph D. 14.3 mph 11. A 500 kg block is pulled up a 2 degree incline by a constant force F of 4 KN. The coefficient of friction between the block and the plane is 0.5. How fast will the block be moving 10 seconds after the pull is applied? Answer: A A. 27.6 m/s B. 34.2 m/s C. 30.4 m/s D. 38.3 m/s 12. A flywheel having a moment of inertia of 25 lbs-ft-sec 2 is revolving with an angular velocity of 10 radians per second when a constant torque of 20 lbs-ft is applied to reverse its direction of rotation. For what length of time must this constant torque act to stop the flywheel and bring up to reverse speed of 5 radians per second? Answer: C A. 12.34 sec B. 14.34 sec C. 18.80 sec
D. 16.34 sec 13. A flywheel having a moment of inertia of 20 kg-m 2 is revolving with an angular velocity of 10 radians per second when a constant torque of 30 N-m is applied to reverse its direction of rotation. For what length of time must this constant torque act to stop the flywheel and bring up to reverse speed of 5 radians per second? Answer: C A. 5 sec B. 12 sec C. 10 sec D. 16 sec 14. A casting weighing 300 lbs is to be lifted by means of an overhead crane. The casting is lifted 10 ft in 12 seconds. What is the horsepower developed? Answer: A A. 0.45 hp B. 8.5 hp C. 6.5 hp D. 9.5 hp
15. A casting of mass of 150 kg is lifted 4 meters in 15 seconds by means of a crane. What is the power? Answer: A A. 392 watts B. 523 watts C. 456 watts D. 634 watts 16. A cast iron flywheel with a mean rim radius of 9 inches, is rotated at a speed of 800 rpm. If the weight of the rim is 20 lbs, what is the centrifugal force? Answer: C A. 3169.34 lbs B. 3262.34 lbs C. 3269.34 lbs D. 4269.34 lbs 17. A steel pulley with a mean rim radius of 120 mm is rotated at a speed of 1100 rpm. If the mass of the rim is 5 kilograms, what is the centrifugal force? Answer: B A. 5344.50 N B. 7961.50 N C. 6432.30 N D. 8734.56 N 18. A round bar made from SAE 1025 low carbon steel is to support a direct tension load of 50,000 lbs. Using a factor of safety of 4, and assuming that the stress concentration factor k = 1. What is the suitable standard diameter. Yield stress is 40,000 psi. Answer: B A. 3 ½ in B. 2 9/16 in C. 2 ¼ in D. 1 ½ in 19. A lever secured to a 2 inches round shaft by steel tapered pin (d=3/8”) has a pull of 50 lbs at a 30 in radius fron shaft center. Find the working stress of the pin. Answer: A
A. B. C. D.
6770 psi 7433 psi 6790 psi 5234 psi
20. A lever secured to a 50 mm round shaft by steel tapered pin (d=10 mm) has a pull of 200 N at a radius of 800 mm. Find the working stress of the pin. Answer: B A. 32.3 Mpa B. 40.6 Mpa C. 45.20 Mpa D. 56.34 Mpa 21. If a shaft of 59 mm diameter is to transmit power of 12 kw at a speed of 500 rpm, find the mean diameter of the pin for a material having a safe unit stress of 40 N/mm 2? Answer: C A. 10 mm B. 14 mm C. 12 mm D. 16 mm
22. Find the thickness of metal required in the hemi-spherical end of a cylindrical vessel, 2 feet in diameter, subjected to an internal pressure of 500 psi. The material is mild steel and a tensile stress of 10,000 psi is allowable. Answer: C A. 0.10 in B. 0.5 in C. 0.3 in D. 0.7 in 23. Find the thickness of metal required in the hemi-spherical end of a cylindrical vessel, 750 mm in diameter, subjected to an internal pressure of 3 N/mm 2. The material is mild steel and a tensile stress of 70 N/mm2 is allowable. Answer: D A. 4 mm B. 2 mm C. 6 mm D. 8 mm 24. What would be the diameter of the line shaft to transmit 10 horsepower if the shaft makes 150 rpm? Answer: D A. 9/16 in B. 3 9/16 in C. 2 9/16 in D. 1 9/16 in 25. What horsepower would be transmitted by a short shaft, 2 inches in diameter, carrying but two pulleys too close to bearings if the shaft makes 300 rpm? Answer: C A. 60 hp B. 75 hp C. 63 hp D. 70 hp
26. What would be the diameter of power transmitting shaft to transmit 150 kw at 500 rpm? Answer: B A. 78 mm B. 81 mm C. 93 mm D. 85 mm 27. What power would a short shaft, 50 mm in diameter, transmit at 400 rpm? Answer: B A. 50 kw B. 60 kw C. 55 kw D. 65 kw 28. Find the torsional deflection for a solid steel shaft 4 inches in diameter and 48 inches long, subjected to twisting moment of 24,000 in-lb. Answer: C A. 0.122 deg B. 0.052 deg C. 0.23 deg D. 0.43 deg 29. Find the torsional deflection of a solid steel shaft, 100 mm in diameter and 1300 mm long, subjected to twisting moment of 3 x 10 6 N-mm. The torsional modulus of elasticity is 80,000 N/mm 2. Answer: B A. 0.122 deg B. 0.285 deg C. 0.234 deg D. 0.534 deg 30. Find the diameter of steel line shaft to transmit 10 hp at 150 rpm with a torsional deflection not to exceeding 0.08 degree foot length. Answer: D A. 0.834 in B. 3.234 in C. 1.23 in D. 2.35 in 31. Find the length in feet of 9/16 inch diameter rope required to fill a drum having the following dimensions: B = 24 in, D = 18 in, H = 30 in. ( K = 0.741). Answer: B A. 1873 ft B. 2560 ft C. 2874 ft D. 2645 ft 32. Find the bending stress and equivalent bending load due to the bending of a 6 x 19 (fiber core) wire rope of ½ in diameter around a 24 in pitch diameter sheave. Answer: B A. 1456 lbs B. 1590 lbs C. 1983 lbs D. 1763 lbs 33. Find the breaking load in pounds of a wrought iron chain crane if the diameter of bar from which links are made is 2 inches. Answer: A
A. B. C. D.
216,000 lbs 416,000 lbs 316,000 lbs 516,000 lbs
34. The specific gravity of cast iron is 7.2. Find the weight of 5 cubic inches of cast iron. Answer: B A. 1.1 lbs B. 1.3 lbs C. 1.2 lbs D. 1.4 lbs 35. The weight of a cubic inch of gold is 0.697 lb. Find the specific gravity. Answer: D A. 13.45 B. 15.34 C. 17.23 D. 19.31
36. If the diameter of driving pulley is 15 inches and its speed, 180 rpm. The diameter of driven pulley is 9 inches. Find the speed of driven pulley. Answer: B A. 100 rpm B. 300 rpm C. 200 rpm D. 400 rpm 37. If the diameter of driving pulley is 24 inches and its speed, 100 rpm, and the driven pulley is to rotate 600 rpm, find the diameter of driven pulley. Answer: D A. 1 in B. 3 in C. 2 in D. 4 in 38. How many ½ inch diameter set-screws would be required to transmit 3 horsepower at a shaft speed of 1000 rpm if the shaft diameter is 1 inch. Answer: A A. 1 B. 1.5 C. 2 D. 2.5 39. How many 3/8 inch diameter set-screws would be required to transmit 3 horsepower at a shaft speed of 1000 rpm if the shaft diameter is 1 inch. Answer: B A. 1 B. 2 C. 1.5 D. 3 40. What is the working strength of a 1 inch bolt which is screwed up tightly in a packed joint when the allowable working stress is 10,000 psi? Answer: A A. 3000 lbs
B. 4000 lbs C. 3500 lbs D. 4000 lbs 41. If the diameter of driven pulley is 36 inches and its required speed, 150 rpm, and speed of driving pulley is 600 rpm, then the diameter of driving pulley is: Answer: B A. 5 in B. 9 in C. 7 in D. 11 in 42. If the diameter of driven pulley is 4 inches and its required speed, 800 rpm, and the diameter of the driver is 26 inches, then the required speed of the driver is: Answer: C A. 112 rpm B. 134 rpm C. 123 rpm D. 145 rpm
43. If the driving gear has 20 teeth and rotates 80 rpm, and the driven gear has 40 teeth, then the speed of the driven gear: Answer: D A. 10 rpm B. 30 rpm C. 20 rpm D. 40 rpm 44. If pitch diameter of the driver is 8 inches, its speed, 75 rpm, and the pitch diameter of the driven gear gear, 20 rpm is: Answer: C A. 20 in B. 40 in C. 30 in D. 50 in 45. If the inertia is 80 lb-ft 2, and the speed of the driven shaft is to be increased from 0 to 1500 rpm in 3 seconds, find the clutch starting torque in lbs. Answer: D A. 100 ft-lb B. 110 ft-lb C. 120 ft-lb D. 130 ft-lb 46. If the inertia is 80 lb-ft 2, and the speed of the driven shaft is to be increased from 0 to 1500 rpm in 3 seconds. Calculate the heat generated for each engagement if clutch starting torque is 10 in-lb. Answer: B A. 20.50 Btu B. 41.50 Btu C. 30.50 Btu D. 51.50 Btu
47. Find the horsepower transmitted by a pair of friction wheels; the diameter of driving wheel is 10 inches, and it revolves at 200 rpm. The width of the wheel is 2 inches. The force per inch width is 150 pound and the coefficient of friction is 0.20. Answer: A A. 0.96 hp B. 0.23 hp C. 1.2 hp D. 1.6 hp 48. A body weighing 28 lbs rests on a horizontal surface. The force required to keep it in motion along the surface is 7 lbs. Find the coefficient of friction. Answer: C A. 0.12 B. 0.45 C. 0.25 D. 0.85 49. Measurement M = 3.495 inches at the gaging notch of a 3 in pipe thread and the wire diameter is 0.07217 in. Find the pitch diameter. (P = 0.125 in). Answer: D A. 1.23 in B. 0.34 in C. 2.34 in D. 3.39 in 50. Find the tooth thickness on the tooth circle of a 14 ½ degree full depth tooth of 12 diametrical pitch. Answer: A A. 0.131 in B. 0.234 in C. 0.455 in D. 0.864 in 51. Find the tooth thickness on the tooth circle of a 20 degree full depth involute tooth having a diametrical pitch of 5. Answer: B A. 0.863 in B. 0.314 in C. 0.108 in D. 0.563 in 52. The outside diameter of a pinion having 10 teeth of 5 diametrical pitch and pressure angle of 14 ½ degrees is to be increased by 0.2746. the circular pitch equivalent to 5 diametrical pitch is 0.6283. Find the arc tooth thickness at the standard pitch diameter. Answer: A A. 0.385 in B. 0.863 in C. 0.543 in D. 0.534 in 53. The outside diameter of a gear having a pressure angle of 14 ½ degrees is to be reduced by 0.2746 in or an amount equal to the increased in diameter of its mating pinion. The circular pitch is 0.6283 in. Determine the circular tooth thickness at the standard pitch diameter. Answer: C A. 0.434 in B. 0.843 in C. 0.243 in D. 0.672 in
54. A pinion has 15 teeth of 3 diametrical pitch. Find the chordal thickness at the standard pitch diameter. Answer: B A. 0.653 in B. 0.523 in C. 0.863 in D. 0.234 in
PART 2: SITUATIONAL PROBLEMS 1. An open belt drive connects a 450 mm driving pulley to another driven pulley 1000 mm in diameter. The belt is 300 mm wide and 10 mm thick. The coefficient of friction of the belt is 0.30 and the mass of the belt is 2.8 kg per meter belt length. Other data are as follows: Center distance between shafts = 4 meters Maximum allowable tensile stress of the belt = 1500 kpa Speed of driving pulley = 900 rpm Determine: 1. The belt density in lb/in3 Answer: C A. 0.014 B. 0.024 C. 0.034 D. 0.044 2. The belt speed in ft/sec Answer: D A. 63.34 B. 65.03 C. 67.37 D. 69.57 3. The angle of contact, rad Answer: A A. 3 rad B. 4 rad C. 5 rad D. 6 rad 4. The power transmitted, kw Answer: B A. 37.45 B. 40.80 C. 43.24 D. 48.34
5. The load at tight side Answer: A A. 1011.47 lbs B. 1111.47 lbs C. 1211.47 lbs D. 1311.47 lbs 6. The load at slack side Answer: C A. 559 lbs B. 569 lbs C. 579 lbs D. 589 lbs
2. A solid transmission shaft is 3.5 inches in diameter. It is desired to replace it with a hollow shaft of the same material and same torsional strength but its weight should only be half as much as the solid shaft. Find: 1. The outside diameter of the shaft Answer: A A. 4.23 in B. 5.34 in C. 7.38 in D. 9.30 in 2. The inside diameter of the shaft Answer: C A. 1.92 in B. 2.56 in C. 3.42 in D. 4.03 in 3. The volume of the hollow shaft per foot length Answer: B A. 53.23 in3 B. 57.74 in3 C. 60.30 in3 D. 63.48 in3 4. The shearing stress of hollow shaft if it used to transmit 150 kw at 6000 rpm, Mpa Answer: D A. 12.84 B. 14.56 C. 16.23 D. 17.63
3. A double threaded right handed worm gear transmits 15 hp at 1150 rpm. The pitch of the worm is 0.75 inches and pitch diameter of 3 inches. The pressure angle is 14 ½° and the coefficient of friction is 0.12. Find: 1. The lead angle Answer: D A. 1.63° B. 3.83° C. 7.23° D. 9.043° 2. The normal pressure angle Answer: C A. 10.327° B. 12.327° C. 14.327° D. 16.327° 3. The worm gear efficiency Answer: A A. 55.13% B. 50.23% C. 58.34% D. 60.34% 4. The power transmitted to gear (output) Answer: B A. 6.39 hp B. 8.27 hp C. 10.27 hp D. 13.47 hp 5. The tangential force on gear Answer: B A. 1,798 lbs B. 1,898 lbs C. 1,998 lbs D. 2,398 lbs 6. The tangential load on the worm Answer: A A. 548 lbs B. 558 lbs
C. 568 lbs D. 578 lbs 7. The separating force Answer: C A. 403 lbs B. 453 lbs C. 501 lbs D. 567 lbs
4. A band brake is installed on a drum rotating at 250 rpm, and a diameter of 900 mm. The angle of contact is 1.5π radians and one end of the brake band is fastened to a fixed pin while the other end to the brake arm 150 mm from fixed end pin. The coefficient of friction is 0.25 and the straight brake arm is 1000 mm long and is placed perpendicular to the diameter bisecting the angle of contact. Determine: 1. The torque transmitted Answer: D A. 2.73 KN-m B. 3.92 KN-m C. 4.16 KN-m D. 1.91 KN-m 2. The tension at the slack side of the brake drum Answer: A A. 1.89 KN B. 2.63 KN C. 3.28 KN D. 4.93 KN 3. The tension at the tight side of the brake drum Answer: B A. 5.33 KN B. 6.14 KN C. 7.83 KN D. 8.28 KN 4. The minimum force in Newtons applied at the end of the brake arm necessary to stop the drum if 50 kw is being absorbed Answer: D A. 125 N B. 150 N C. 175 N D. 200 N 5. A steel band with maximum tensile stress of 55 Mpa and 3.0 mm thick will be used. What should be its width in millimeters? Answer: A A. 37 mm B. 39 mm C. 41 mm
D. 43 mm
5. A helical compression spring has scale of 400 lbs/inch, an inside diameter of 2.5 inches, a free length of 8 inches and with squared and ground ends. Material is to be chrome vanadium steel with working stress of 63,000 psi and G = 10,800,000 psi. For a load of 825 lbs, and for an average service, Whall factor, k = 1.25. Determine: 1. The standard size wire diameter Answer: B A. ¼ in B. ½ in C. ¾ in D. 1 ¼ in 2. The spring index Answer: A A. 6 B. 7 C. 8 D. 9 3. Number of active coils Answer: D A. 8.23 B. 11.23 C. 5.34 D. 7.81 4. The solid height Answer: C A. 2.83 in B. 3.26 in C. 4.91 in D. 6.34 in 5. The stress at solid height Answer: A A. 94,546 psi B. 95,735 psi C. 96,735 psi D. 97,735 psi
6. A 2 ½ inches double square thread with two threads/inch is to be used. The frictional radius of the collar is 2 inches and the coefficient of friction are 0.10 for the threads and 0.15 for the collar. The velocity of the nut is 10 ft/min. For a lifting load of 4000 lbs, find: 1. The lead angle Answer: D A. 5.23° B. 6.27° C. 7.94° D. 8.05° 2. The torque required to turn the screw Answer: A A. 1102.35 in-lbs B. 1293.65 in-lbs C. 1493.65 in-lbs D. 1693.65 in-lbs 3. The torque required to overcome collar friction Answer: B A. 1000 in-lbs B. 1200 in-lbs C. 1400 in-lbs D. 1600 in-lbs 4. The efficiency of the screw Answer: C A. 25.58% B. 26.58% C. 27.65% D. 28.58% 5. The power input of the screw Answer: B A. 1.37 hp B. 4.38 hp C. 7.37 hp D. 9.37 hp
7. A 16 mm plate is lapped over and secured by fillet weld on the inside and outside to form a penstock 1.5 m diameter. An allowable stress of 140 Mpa on the plate and an allowable shearing stress of 90 Mpa on the throat side of the 14 mm fillet weld. Determine: 1. The internal pressure that can be carried by the plate Answer: A A. 3 Mpa B. 5 Mpa C. 7 Mpa D. 9 Mpa 2. The internal pressure that can be carried by the welded joint Answer: B A. 1.38 Mpa B. 2.38 Mpa C. 3.38 Mpa D. 4.38 Mpa 3. The thickness of the plate if the internal pressure is 2 Mpa (neglecting welded joint) Answer: A A. 16.67 mm B. 18.67 mm C. 14.67 mm D. 12.67 mm 4. The thickness of the plate if the internal pressure is 20 Mpa (neglecting welded joint) Answer: D A. 130.17 mm B. 160.17 mm C. 170.17 mm D. 190.17 mm 5. Factor of safety of the plate if ultimate stress is 450 Mpa Answer: C A. 3 B. 4 C. 5 D. 6
8. A safety valve spring having 9-1/2 coils has the ends squared and ground. The outside diameter is 115 mm and wire diameter is 13 mm. It has a free length of 203 mm. The spring must be initially compressed to hold the boiler pressure of 1.38 Mpa on the valve seat of 32 mm diameter. Modulus of rigidity is taken as G = 80 Gpa. Determine: 1. The force acting on the spring Answer: B A. 0.811 KN B. 1.11 KN C. 1.45 KN D. 1.87 KN 2. The spring index Answer: B A. 6.85 B. 7.85 C. 8.85 D. 9.85 3. The coil deflection Answer: A A. 31 mm B. 33 mm C. 35 mm D. 45 mm 4. The compressed length of the spring Answer: D A. 142 mm B. 152 mm C. 162 mm D. 172 mm 5. The spring stress if it is compressed to its solid length Answer: C A. 360 Mpa B. 380 Mpa C. 400 Mpa D. 420 Mpa
9. The large diameter and face of the disk of a multiple disk clutch are 255 mm and 25 mm respectively. The helical compression spring used to engaged the clutch has 9-1/2 efeective coils of 10 mm steel wire. The outer coil diameter is 80 mm. the free length of the spring is 185 mm. When in place with clutch engaged, its length is 130 mm. Assuming that there are 10 pairs of friction surface in contact, that the motor runs at 1200 rpm, with coefficient of friction on contatct surface f = 0.15, ( G = 80 Gpa), determine: 1. The axial force available for the clutch Answer: A A. 1.69 KN B. 2.69 KN C. 3.69 KN D. 4.69 KN 2. The mean frictional radius Answer: C A. 125.45 mm B. 145.45 mm C. 115.45 mm D. 155.45 mm 3. The torque transmitted Answer: B A. 0.192 KN-m B. 0.292 KN-m C. 0.392 KN-m D. 0.492 KN-m 4. The power that the clutch can transmit Answer: D A. 30.69 Kw B. 32.69 Kw C. 34.69 Kw D. 36.69 Kw
10. An electric motor running at 1200 rpm drives a punch press shaft at 200 rpm by means of a 130 mm wide and 8 mm thick belt. When the clutch is engaged the belt slips. To correct this condition, an idler pulley was installed to increase the angle of contact but the same belt and pulley were used. The original contact angle on the 200 mm motor pulley is 160 degrees. The original tension ratio is 2.4 and the net tension is 12 N/mm of the belt width. If an increase in transmission capacity of 20% will prevent slippage, determine: 1. The coefficient of friction Answer: A A. 0.313 B. 0.413 C. 0.513 D. 0.613 2. The tension at the tight side in the original installation Answer: B A. 2.37 KN B. 2.67 KN C. 2.97 KN D. 3.67 KN 3. The tension at the slack side in the original installation Answer: D A. 2.22 KN B. 3.33 KN C. 4.44 KN D. 1.11 KN 4. The tension at the slack side when the idler was installed Answer: C A. 0.452 KN B. 0.653 KN C. 0.802 KN D. 1.290 KN 5. The new angle of contact Answer: B A. 210° B. 220° C. 230° D. 240°
11. A four wheel vehicle must developed a draw bar pull of 17,500 lbs. The engine, which develops 500 hp and drives through a gear transmission a 34-tooth spiral bevel pinion gear which meshes with a spiral bevel gear having 51 teeth. Determine: 1. The speed of the wheels Answer: B A. 55 rpm B. 60 rpm C. 65 rpm D. 70 rpm 2. The speed of shaft Answer: C A. 80 rpm B. 85 rpm C. 90 rpm D. 95 rpm 3. The transmission gear ratio should be used if the engine develops maximum torque at 1500 rpm Answer: D A. 12.67 : 1 B. 13.67 : 1 C. 14.67 : 1 D. 16.67 : 1 4. The torque required per wheel, in-lbs Answer: A A. 210,000 B. 220,000 C. 230,000 D. 240,000 5. The axial diameter for an allowable torsional stress at 12,000 psi, the efficiency of the bevel gear differential is 80% Answer: A A. 4 ½ in B. 1 ½ in C. 2 ½ in D. 3 ½ in
12. The smaller of two concentric helical springs is made of 22 mm diameter steel spring and has an outside diameter of 100 mm with 10 active coils. The outer spring is made of 32 mm steel spring and has an outer diameter of 250 mm with 8 active coils. Before the load is applied, the outer spring is 25 mm longer than the inner spring. If the load of 90 KN is applied to the nest of the springs. (G = 80 Gpa). 1. Find the spring rate of the inner spring Answer: A A. 493.80 KN/m B. 593.80 KN/m C. 693.80 KN/m D. 793.80 KN/m 2. Find the spring rate of outer spring Answer: A A. 126.50 KN/m B. 136.50 KN/m C. 146.50 KN/m D. 156.50 KN/m 3. Find the load carried by the inner spring Answer: C A. 49.13 KN B. 59.13 KN C. 69.13 KN D. 79.13 KN 4. Find the load carried by the outer spring Answer: B A. 10.87 KN B. 20.87 KN C. 30.87 KN D. 40.87 KN 5. Find the percentage load carried by the inner spring Answer: D A. 70.81% B. 72.81% C. 74.81% D. 76.81%
13. A flange coupling connects two 2” diameter shafts. The flanges are fitted with 6 bolts of SAE 1040 steel on a 7” bolt circle. The shafts runs at 300 rpm and transmits 45 hp. Assume a factor of safety of 5, ultimate tension of 70,000 psi, and ultimate shear of 55,000 psi. Determine: 1. The torque transmitted Answer: B A. 8,453.80 in-lbs B. 9,453.80 in-lbs C. 10,453.80 in-lbs D. 11,453.80 in-lbs 2. The force applied per bolt Answer: C A. 451.17 lbs B. 430.17 lbs C. 450.17 lbs D. 470.17 lbs 3. The diameter of the bolt required Answer: A A. 0.228 in B. 0.328 in C. 0.428 in D. 0.528 in 4. The thickness of flanged to be used Answer: A A. 0.141 in B. 0.241 in C. 0.341 in D. 0.541 in 14. A simple band brake has a 76 cm drum and fitted with steel band 2/5 cm thick lined with a brake lining having a coefficient of friction of 0.25. The arc of contact is 245°. The drum is attached to a 60 cm hoisting drum that sustains a rope load of 820 kg. The operating force has a moment arm of 1.50 m and the band is attached 12 cm from the pivot point. Find: 1. The torque just required to support the load (clockwise) Answer: C A. 2,013.26 N-m B. 2,213.26 N-m
C. 2,413.26 N-m D. 2,613.26 N-m 2. The tension at the slack side of the brake Answer: A A. 3321.50 N B. 3421.50 N C. 3521.50 N D. 3621.50 N 3. The operating force at the end of brake arm Answer: A A. 773.80 N B. 775.80 N C. 777.80 N D. 779.80 N 4. The width of a steel band for a tensile stress of 50 Mpa Answer: D A. 40.40 mm B. 44.40 mm C. 46.40 mm D. 48.40 mm
15. A mechanical press is used to punch 6 holes per minute on a 25 mm thick plate. The hole is 25 mm in diameter and the plate and has an ultimate strength in shear of 420 Mpa. The normal operating speed is 200 rpm and it slows down to 180 rpm during the process of punching. The flywheel has a mean diameter of one meter and the rim width is 3 times the thickness. Assume that the hub and arm account for 5% of the rim weight concentrated at the mean diameter and density of cast iron is 7,200 kg per cubic meter. Find: 1. The maximum force required to punched a hole Answer: B A. 804.67 KN B. 824.67 KN C. 844.67 KN D. 864.67 KN 2. The power required to drive the press Answer: B A. 0.833 kw B. 1.031 kw C. 1.56 kw D. 2.13 kw 3. The flywheel weight Answer: D A. 3.23 KN B. 5.39 KN C. 7.38 KN D. 9.71 KN 4. The thickness of the rim Answer: A A. 118 mm B. 130 mm C. 162 mm D. 184 mm 5. The width of the rim Answer: D A. 324 mm B. 334 mm C. 344 mm D. 354 mm
16. A flange coupling is to connect two 57 mm shafts. The hubs of the coupling are each 111 mm in diameter and 92 mm thick and the flange web are 19 mm thick. Six 16 mm bolts in a 165 mm diameter circle connect the flanges. The keyway is 6 mm shorter than the hub’s thickness and the key is 14 mm x 14 mm. Coupling is to transmit 45 kw at 160 rpm. For all parts, yield point value in shear is one-half the yield value which is 448 Mpa. Find the following: 1. The force on the shaft Answer: A A. 94.25 KN B. 90.23 KN C. 86.34 KN D. 80.34 KN 2. The factor of safety in the shear key Answer: B A. 1.83 B. 2.86 C. 3.48 D. 5.34 3. The factor of safety in bearing key Answer: D A. 5.34 B. 4.23 C. 3.20 D. 2.86 4. The force applied per bolt coupling Answer: A A. 5.43 KN B. 6.94 KN C. 7.39 KN D. 8.39 KN 5. The factor of safety in shear of bolts Answer: C A. 6.39 B. 7.39 C. 8.30 D. 9.30
17. A hydraulic control for a straight motion utilizes a spherical pressure tank “A” that is connected to a work cylinder “B”. “A” maintains pressure in the tank at 4000 psi. 1. The tank is 32 inches in diameter, welded with 100% joint efficiency and made of steel plates with an allowable tensile strength of 7,500 psi. Calculate the required thickness of the tank. Answer: B A. 0.23 in B. 0.43 in C. 0.54 in D. 0.65 in 2. The pressure drop between tank and the cylinder is 30 psi. Assume allowance for friction in the cylinder and packing to be 10 percent of F, the operating force. Calculate the diameter of the piston if value of F is 5000 lbs. Answer: D A. 1.27 in B. 2.39 in C. 3.29 in D. 4.35 in 3. Determine the wall thickness of work cylinder B if it is made of cast iron having an allowable tensile stress of 2,000 psi. Answer: A A. 0.488 in B. 0.560 in C. 0.653 in D. 0.837 in 4. The piston stroke of the work cylinder is 18 inches; the time of a work stroke is 5 seconds. Calculate the horsepower output of the cylinder. Answer: C A. 1.29 hp B. 4.23 hp C. 2.73 hp D. 5.34 hp
5. Assume that the work cycle of the piston rod occurs every 30 seconds, that the overall efficiency of the hydraulic control is 80 percent, and the pump efficiency is 60 percent, determine the horsepower of the motor continuously operating the slump. Answer: C A. 0.25 hp B. 5.34 hp C. 0.95 hp D. 1.27 hp
18. Consider a 304.8 mm section of a single-riveted lap joint made up with plates of 6.35 mm thickness and 6 rivets, 15.87 mm in diameter. Assume that the rivet holes are 1.58 mm larger in diameter than the rivets. In this joint, the entire load is transmitted from one plate to the other by means of rivets. Each plate and the six rivets carries the entire load. Design stress for shear is 598 kg/cm 2, for bearing, 1406 kg/cm2, and for tension, 703 kg/cm 2. Assume that the rivets will not tear or shear through the plate to the edge of the joints. Find: 1. The force that can be carried by unpunched plate Answer: A A. 13,606.40 kg B. 16,606.40 kg C. 17,606.40 kg D. 19,606.40 kg 2. The force to cause tensile stress on plate between rivets Answer: C A. 6,394.56 kg B. 7,083.09 kg C. 8,932.6 kg D. 9,099.45 kg 3. The force to cause shearing stress on rivets Answer: B A. 7,580.90 kg B. 8,580.90 kg C. 9,580.90 kg D. 10,580.90 kg 4. The force to cause bearing stress on rivets Answer: A A. 9,347.70 kg B. 10,347.70 kg C. 11,347.70 kg D. 12,347.70 kg 5. The efficiency Answer: B A. 563.4%
B. 63.06% C. 60.45% D. 76.34% 19. A 76 mm solid shaft is to be replaced with a hollow shaft of equal torsional strength. The outside diameter of the hollow shaft is 100 mm. 1. The inside diameter of hollow shaft Answer: A A. 86.55 mm B. 88.34 mm C. 90.28 mm D. 92.34 mm 2. The percentage of weight saved Answer: C A. 50.34% B. 53.34% C. 56.56% D. 65.34%
20. The engine of a motor vehicle with a wheel diameter of 712 mm develops 50 kw at 2,000 rpm. The combined efficiency of the differential and transmission is 75% with an overall speed reduction of 25 is to 1. Determine: 1. Torque to be delivered by the clutch in N-m Answer: B A. 224 N-m B. 239 N-m C. 245 N-m D. 265 N-m 2. Axial force on the clutch in KN. Outside and inside diameter of the clutch are 300 mm and 240 mm respectively. There are two pairs of mating surface with a coefficient of friction of 0.30. ( Use uniform wear method). Answer: B A. 2.34 KN B. 2.95 KN C. 3.25 KN D. 4.39 KN 3. Torque on wheels Answer: D A. 1.234 KN B. 2.56 KN C. 3.56 KN D. 4.476 KN 4. Draw bar pull developed in KN Answer: A A. 12.57 KN B. 15.23 KN C. 17.30 KN D. 19.39 KN 5. Speed of travel of the vehicle in km/hr Answer: C A. 5.34 km/hr B. 7.49 km/hr
C. 10.74 km/hr D. 12.03 km/hr 21. A single threaded trapezoidal metric thread has a pitch of 4 mm and a mean diameter of 18 mm. It is used as a translation screw in conjunction with a collar having an outside diameter of 37 mm and an inside diameter of 27 mm. The load is 400 kg and coefficient of friction is 0.3 for both threads and collar. Find: 1. The collar torque Answer: A A. 1920 kg-mm B. 1763 kg-mm C. 1890 kg-mm D. 2003 kg-mm 2. The torque required for thread Answer: D A. 1293 kg-mm B. 1192 kg-mm C. 1598 kg-mm D. 1401 kg-mm 3. The total torque Answer: C A. 1083 kg-mm B. 2089 kg-mm C. 3321 kg-mm D. 4873 kg-mm 22. It is found that the shearing machine requires 205 joules of energy to shear a specific gauge of sheet metal. The mean diameter of the flywheel is to be 76.20 cm. The normal operating speed is 200 rpm, and slows down to 180 rpm during shearing process. The width is 30.48 cm, and the weight of cast iron is 7,196.60 kg/m3. The arms and hub account for 10% of the rim weight concentrated at mean diameter. Determine: 1. The rim weight Answer: A A. 33.88 kg B. 35.23 kg C. 37.23 kg D. 39.45 kg 2. The thickness of the rim Answer: D A. 0.145 cm B. 0.345 cm C. 0.764 cm D. 0.587 cm 23. A double reaction gear assembly is mounted on three parallel shafts located on the same horizontal plane. Shaft A is driven from a 2 kw source at 3,500 rpm. The pinion on shaft A has 24 teeth and meshes with a gear on shaft B. Another pinion on shaft B is in mesh with a gear on shaft C with 160 teeth. The centerline distance between shaft A and shaft C is 154 times the module. The overall gear train ratio is 14:1. Assume module for all gears are the same, determine: 1. The speed of shaft B Answer: A A. 1000 rpm B. 1100 rpm C. 1200 rpm D. 1300 rpm 2. The number of teeth on gears at shaft B Answer: A A. 84 & 40 teeth
B. 84 & 50 teeth C. 84 & 60 teeth D. 84 & 70 teeth 3. The torque on shaft A Answer: C A. 3.28 N-m B. 4.34 N-m C. 5.46 N-m D. 6.94 N-m 4. The torque on shaft B Answer: D A. 10.23 N-m B. 13.45 N-m C. 16.39 N-m D. 18.14 N-m 5. The torque on shaft C Answer: B A. 56.34 N-m B. 68.95 N-m C. 73.23 N-m D. 78.30 N-m
24. A key is to be desired for a 12.7 cm, shaft which will transmit power of 150 kw at 360 rpm. If allowable shear stress for the key is 920 kg/cm 2 and the allowable compressive stress is 1200 kg/cm 2, determine the following: 1. Cross-sectional dimensions of the flat key to be used Answer: B A. 1.11 cm B. 2.22 cm C. 3.33 cm D. 4.44 cm 2. Force acting on a key Answer: A A. 62.66 KN B. 64.34 KN C. 66.04 KN D. 68.34 KN 3. Length of key under shearing stress Answer: D A. 7.34 cm B. 6.31 cm C. 4.23 cm D. 2.19 cm 4. Length of key under compressive stress Answer: C A. 2.03 cm B. 3.49 cm C. 4.79 cm D. 5.34 cm 5. Safe length of key to be used Answer: B A. 2.03 cm B. 4.79 cm C. 6.34 cm D. 8.03 cm
6. Axial force to remove the hub from the shaft if the coefficient of friction is 0.45 Answer: B A. 45.23 KN B. 56.40 KN C. 58.34 KN D. 65.45 KN
25. A pinion rotating at 1800 rpm and supported on each side by a ball bearing transmits 18 kw to a mating spur gear. If the pressure angle is 20 degrees and the pitch diameter is 102 mm, determine the following: Note: Add 3 degrees to the pressure angle to compensate for the friction 1. Pitch line velocity Answer: B A. 8.10 m/sec B. 9.61 m/sec C. 11.02 m/sec D. 13.03 m/sec 2. Torque transmitted by the pinion Answer: D A. 65.34 N-m B. 75.23 N-m C. 87.23 N-m D. 95.49 N-m 3. Tangential load on gears Answer: C A. 1,563 N B. 1,754 N C. 1,872 N D. 1,908 N 4. Separation load on gears Answer: A A. 794.6 N B. 872.3 N C. 982.3 N D. 1,735.8 N 5. Total load on gears Answer: A A. 2,034 N B. 3,034 N
C. 4,034 N D. 5,034 N
26. A dumb waiter designed to travel a height of 3 m when loaded will have a maximum gross weight of 100 kg. A coil spring is provided below to absorb shock in the event that the dumb waiter should fall freely because of sudden breakage of the wire rope carrying it. If the coil spring will be deflected to 30.48 cm, if the dumb waiter should accidentally fall and it hit the spring from its maximum height of travel, determine the following: Note: Use spring index of 8 and assume maximum induce stress and shear modulus of elasticity to be 3868 kg/cm2 and 808,720 kg/cm2, respectively 1. Whaal factor Answer: D A. 1.045 B. 1.863 C. 1.564 D. 1.184 2. Maximum force acting on spring Answer: B A. 1872.34 kg B. 2168.50 kg C. 2235.40 kg D. 2634.66 kg 3. Wire diameter Answer: C A. 1.20 cm B. 2.34 cm C. 3.68 cm D. 41.23 cm 4. Mean coil diameter Answer: A A. 29.42 cm B. 34.23 cm C. 37.45 cm D. 41.23 cm
5. Number of active coils Answer: A A. 10.20 B. 14.23 C. 16.34 D. 18.34
27. The maintenance shop of PAL has a motor operated hoisting which consists of the following mechanical parts: Motor shaft “A” is fitted with a double threaded left handed worm in mesh with 56 tooth worm wheel at shaft “B” directly below. Compounded on shaft “B” is a 20 tooth 5 module pinion in mesh with a spur gear keyed on shaft “C” with a horizontal center line distance of 150 mm. Mounted on the same shaft “C” is a 200 mm diameter hoisting drum. The cable wrap around the drum sustains a load of 500 kg at motor speed of 1750 rpm. Determine the following: 1. Pitch diameter of pinion Answer: A A. 100 mm B. 102 mm C. 104 mm D. 108 mm 2. Pitch diameter of spur gear Answer: C A. 180 mm B. 190 mm C. 200 mm D. 210 mm 3. Speed of shaft C Answer: B A. 27.34 rpm B. 31.25 rpm C. 34.24 rpm D. 39.45 rpm 4. Power at shaft C Answer: B A. 1.45 kw B. 1.894 kw C. 1.605 kw D. 2.083 kw 5. Torque at shaft A Answer: D
A. 7.234 N-m B. 9.563 N-m C. 11.23 N-m D. 13.47 N-m 6. Velocity of the load Answer: C A. 0.213 m/sec B. 0.189 m/sec C. 0.327 m/sec D. 0.485 m/sec
28. A machine shop somewhere in Quezon City fabricated a pair of spur gear 2.5 module and to be mounted on shafts with center line distance of 90 mm. The speed ratio required is 3:1. Determine the following: 1. Pitch diameter of the gear Answer: A A. 135 mm B. 140 mm C. 145 mm D. 150 mm 2. Number of teeth of the gear Answer: C A. 50 teeth B. 52 teeth C. 54 teeth D. 56 teeth 3. Circular pitch Answer: B A. 6.23 mm B. 7.85 mm C. 8.37 mm D. 9.02 mm 4. Addendum distance Answer: A A. 2.50 mm B. 3.0 mm C. 3.5 mm D. 4.0 mm 5. Clearance Answer: D A. 0.125 mm B. 0.250 mm C. 0.425 mm
D. 0.625 mm 6. Dedendum distance Answer: B A. 2.33 mm B. 3.125 mm C. 4.66 mm D. 5.99 mm 7. Whole depth Answer: D A. 2.38 mm B. 3.02 mm C. 4.36 mm D. 5.625 mm 8. Working depth Answer: C A. 3 mm B. 4 mm C. 5 mm D. 6 mm 9. Tooth thickness Answer: A A. 3.93 mm B. 4.34 mm C. 5.38 mm D. 6.34 mm
10. Space width Answer: B A. 3 mm B. 4 mm C. 5 mm D. 6 mm 11. Outside diameter of the gear Answer: C A. 120 mm B. 130 mm C. 140 mm D. 150 mm 12. Root diameter of pinion Answer:D A. 28.75 mm B. 32.34 mm C. 17.45 mm D. 38.75 mm 29. A pulley is keyed to a 2 ½ inches diameter shaft by a 5/8 x 7/16 in x 3 in flat key. The shaft rotates at 50 rpm. The allowable shearing stress for the key is 22 ksi. The allowable compressive stress for the key, hub and shaft are 66 ksi, 59 ksi, and 72 ksi, respectively. Determine: 1. The torque that can be carried due to shearing stress of the key Answer: A A. 51,562.50 in-lbs B. 61,562.50 in-lbs C. 71,562.50 in-lbs D. 81,562.50 in-lbs 2. The torque that can be carried due to compressive stress of key Answer: C A. 50,110.60 in-lbs B. 52,110.60 in-lbs
C. 54,110.60 in-lbs D. 56,110.60 in-lbs 3. The torque that can be carried by the shaft Answer: B A. 57,495.10 in-lbs B. 67,495.10 in-lbs C. 77,495.10 in-lbs D. 87,495.10 in-lbs 4. The torque that can be carried by the hub Answer: D A. 42,398.44 in-lbs B. 44,398.44 in-lbs C. 46,398.44 in-lbs D. 48,398.44 in lbs 5. The maximum torque the pulley can safely delivered Answer: D A. 42,398.44 in-lbs B. 44,398.44 in-lbs C. 46,398.44 in-lbs D. 48,398.44 in lbs
30. A double thread ACME thread screw driven by a motor at 400 rpm raises the attached load of 900 kg at a speed of 10m/min. The screw has pitch diameter of 36 mm. The coefficient of friction on threads is 0.15. The friction torque on the thrusts bearing of the motor is taken to be 20% of the total torque point input. Determine: 1. The lead Answer: A A. 25 mm B. 30 mm C. 35 mm D. 40 mm 2. The lead angle Answer: B A. 10.23° B. 12.46° C. 14.34° D. 16.23° 3. The torque required to turn the screw Answer: B A. 4.23 kg-m B. 6.31 kg-m C. 8.45 kg-m D. 10.23 kg-m 4. The total torque input Answer: D A. 0.017327 KN-m B. 0.037327 KN-m C. 0.057327 KN-m D. 0.07428 KN-m 5. The motor required to operate the screw Answer: C A. 1.239 kw B. 2.239 kw
C. 3.110 kw D. 4.239 kw
31. A gear having 60 teeth is being driven by a 12-tooth gear running at 800 rpm. Determine the following: 1. The speed of the driven gear Answer: B A. 150 rpm B. 160 rpm C. 170 rpm D. 180 rpm 2. The speed of driven gear if a 24 tooth idler is placed between the driving and driven gear Answer: B A. 150 rpm B. 160 rpm C. 170 rpm D. 180 rpm 3. The speed of driven gear if a two 24 tooth idler is placed between the driving and driven gear Answer: B A. 150 rpm B. 160 rpm C. 170 rpm D. 180 rpm 4. The direction of rotation of the driven gear when one idlers are used Answer: A A. The same B. opposite C. ahead D. none of these 5. The direction of rotation of the driven gear when two idlers are used Answer: B A. The same B. opposite
C. ahead D. none of these
32. A disc clutch having an outside diameter of 32 cm and an inside diameter of 12.7 cm is connected to an engine that turns at 750 rpm. The coefficient of friction is 0.60 while the pressure between the friction surfaces is 2 kg/cm2. 1. Force on the clutch pedal necessary to disengaged the clutch disc from the engine using uniform pressure Answer: C A. 1,155.14 kg B. 1,255.14 kg C. 1,355.14 kg D. 1,455.14 kg 2. Mean friction radius Answer: A A. 11.87 cm B. 12.87 cm C. 13.87 cm D. 14.87 cm 3. Clutch torque Answer: D A. 0.6467 KN-m B. 0.7467 KN-m C. 0.8467 KN-m D. 0.9467 KN-m 4. Power transmitted by the engine Answer: D A. 71.35 kw B. 72.35 kw C. 73.35 kw D. 74.35 kw
33. Two short shafts having identical diameters of 38.1 mm and rotating at 400 rpm are connected by a flange coupling having 4 bolts with a 100 mm bolt circle. The design shearing stress of the bolt is 12 Mpa and design compressive stress of the flange is 15 Mpa. 1. What is the power transmitted by the short shaft? Answer: C A. 20.50 kw B. 24.50 kw C. 26.50 kw D. 28.50 kw 2. What is the torque transmitted by the shaft? Answer: D A. 0.032 KN-m B. 0.232 KN-m C. 0.432 KN-m D. 0.632 KN-m 3. What diameter of bolt should be used? Answer: C A. ¼ in B. ½ in C. ¾ in D. 1 in 4. How thick should the flange be in mm? Answer: D A. 7.07 mm B. 5.07 mm C. 9.07 mm D. 11.07 mm
34. Two shafts are connected by spur gears. The pitch radii of the gears A and B are 207 mm and 842 mm respectively. If shaft A makes 350 rpm and is subjected to twisting moment of 236 N-m. Pressure angle is 14.5°. What is: 1. Rpm of gear B Answer: A A. 86 rpm B. 88 rpm C. 90 rpm D. 92 rpm 2. Torque in shaft B Answer: C A. 920 N-m B. 940 N-m C. 960 N-m D. 980 N-m 3. Separation load of the gears Answer: A A. 294.82 N B. 296.82 N C. 298.82 N D. 300.82 N 4. Total load on gears Answer: B A. 1166 N B. 1177 N C. 1188 N D. 1199 N
35. A rectangular key was used in a pulley connected to a line shaft with a power of 7.46 KW at a speed of 1200 rpm. If the shearing stress of the shaft and key are 30 Mpa and 240 Mpa,respectively: 1. What is the diameter of the shaft? Answer: B A. 18.60 mm B. 21.60 mm C. 26.60 mm D. 29.60 mm 2. What is the length of the rectangular key if the width is one fourth of the shaft diameter? Answer: B A. 3.24 mm B. 4.24 mm C. 5.24 mm D. 6.24 mm
36. A pulley 610 mm in diameter transmits 40 kw at 500 rpm. The arc of contact between the belt and pulley is 144 degrees, the coefficient of friction between belt and pulley is 0.35 and the safe working stress of the belt is 2.1 Mpa. It is required to find: 1. The tangential force at the rim of the pulley in Newtons Answer: B A. 2,405 N B. 2,505 N C. 2,605 N D. 2,705 N 2. The effective belt pull in Newtons Answer: C A. 2,305 N B. 2,405 N C. 2,505 N D. 2,605 N 3. The width of the belt used if its thickness is 6 mm Answer: A A. 340 mm B. 250 mm C. 360 mm D. 370 mm 37. A steel shaft transmits 40 hp at 1400 rpm. Considering allowable shearing stress based on pure torsion to be 5000 psi, find: 1. The shaft diameter of nearest commercial size Answer: B A. 1 ¼ in B. 1 7/16 in
C. 2 7/16 in D. 1 ¾ in 2. The torsional deflection on the shaft in degrees per foot Answer: A A. 0.246 degrees B. 0.256 degrees C. 0.266 degrees D. 0.276 degrees 38. A Pajero jeep wagon’s develops 40 kw at 1200 rpm, with single plate clutch with two pairs of friction surfaces transmitting the power. Consider the coefficient of friction to be 0.30 and mean diameter of disc to be 200 mm, determine: 1. Axial force required to engage the clutch and transmit the power Answer: A A. 5.305 KN B. 5.405 KN C. 5.505 KN D. 5.605 KN 2. Inside and outside diameter of the discs and the face width if the maximum pressure is limited to 200 Kpa Answer: A A. 61 mm B. 63 mm C. 65 mm D. 67 mm
39. With the present water interruptions prevailing in Metro Manila, you have been asked to design an upright cylindrical water tank 6 meter in diameter and 6 m high, vented, and to be filled completely with water. 1. Determine the minimum thickness of the tank plate if the stress is limited to 40 Mpa Answer: C A. 2,405 N B. 2,505 N C. 2,605 N D. 2,705 N 2. If the water tank had to be elevated 10 meters from its bottom and has to be filled up in 2 hours, determine the pump capacity needed to fill the tank and motor power to drive the pump if velocity and head loss is 5 meters. Consider pump efficiency of 70% and motor efficiency of 85%. Answer: D A. 5.16 kw B. 6.16 kw C. 7.16 kw D. 8.16 kw 40. A 48 in diameter diamond saw blade is mounted on a pulley driven steel shaft, requiring a blade perimeter linear speed of 150 ft/sec. Motor drive is 125 hp at 1200 rpm, with 6 inches diameter pulley. Determine: 1. The shaft rpm to attain blade peripheral speed required Answer: C A. 712.20 rpm B. 714.20 rpm
C. 716.20 rpm D. 718.20 rpm 2. The shaft diameter Answer: A A. 2.10 in B. 2.20 in C. 2.30 in D. 2.40 in 3. The shaft pulley diameter Answer: B A. 5.053 in B. 10.053 in C. 15.053 in D. 20.053 in
41. In an LRT II project, steel railroad rails of 10 m long are to be installed. If lowest temperature considered is 16°C, and a maximum temperature of 36°C is designed for, assuming coefficient of thermal expansion of steel to be 11.6 x 10 -6 m/m-°C and modulus of elasticity of steel to be 207,000 Mpa. 1. Determine the clearance between rails such that the adjoining rail will just touched at maximum design temperature Answer: C A. 1.23 mm B. 1.56 mm C. 2.32 mm D. 3.23 mm 2. Should the excessive high summer temperature of 40°C occur, determine the induced stress in the rails at that temperature Answer: B A. 8.34 Mpa B. 9.605 Mpa C. 10.56 Mpa D. 12.34 Mpa 42. A flange coupling has an outside diameter of 200 mm and connects two 40 mm shafts. There are four 16 mm bolts on a 140 mm bolt circle. The radial flange thickness is 20 mm. If the torsional stress in the shaft is not to exceed 26 Mpa, determine: 1. The power that can be transmitted at 600 rpm Answer: B A. 17.12 kw B. 20.53 kw C. 24.23 kw D. 32.23 kw
2. The shearing stress in the bolts if uniformly distributed Answer: D A. 1.29 Mpa B. 2.34 Mpa C. 3.04 Mpa D. 5.804 Mpa 3. The maximum shearing stress induced in the bolts Answer: A A. 111.65 Mpa B. 113.65 Mpa C. 115.65 Mpa D. 117.65 Mpa 4. The bearing pressure in the bolts Answer: C A. 2.34 Mpa B. 1.03 Mpa C. 3.65 Mpa D. 5.34 Mpa
43. A square single thread jackscrew has 2 threads per inch. It is to lift 15 tons. The friction radius of the collar is 1 inch. The coefficient of friction between the threads of the screw and base is 0.15,that between the screw and collar is 0.13. Determine: 1. The diameter of the root of the screw if the allowable stress in compression is 6,000 psi Answer: C A. 0.45 in B. 1.50 in C. 2.75 in D. 3.85 in 2. The torque required to turn the screw Answer: D A. 6826.45 in-lbs B. 7834.40 in-lbs C. 8734.57 in-lbs D. 9120.60 in-lbs 3. The pull required at the end of a 5 ft bar raises the load Answer: A A. 218.51 in-lbs B. 245.23 in-lbs C. 265.30 in-lbs D. 287.45 in-lbs 4. The twisting moment exerted at the root of the threads Answer: A A. 9120.60 in-lbs B. 9563.40 in-lbs C. 9304.56 in-lbs D. 9873.45 in-lbs 5. The power output of the screw if it is turning at 60 rpm Answer: D
A. 1.87 hp B. 4.20 hp C. 3.04 hp D. 2.27 hp 6. The power input of the screw Answer: B A. 10.28 hp B. 12.46 hp C. 14.93 hp D. 16.93 hp 7. The efficiency of the screw and collar Answer: C A. 12.39% B. 14.39% C. 18.23% D. 16.29%
44. A 200 mm cast iron pulley is fastened to a 112.50 mm shaft by means of a 28.13 mm square key 175 mm long. The key and shaft are SAE 1030 steel annealed with allowable shearing of key of 29,400 psi and compressive of 6765.3 kg/cm2 1. Force required to shear the key Answer: A A. 997.59 KN B. 873.45 KN C. 756.03 KN D. 652.34 KN 2. Force needed to compress the key Answer: C A. 1431.93 KN B. 1596.24 KN C. 1633.36 KN D. 1763.48 KN 3. Safe power of the shaft at 600 rpm Answer: B A. 2083.54 KW B. 3525.77 KW C. 4823.49 KW D. 5623.74 KW 4. What force acting at the pulley rim will shear this key? Answer: A A. 93.52 KN B. 85.27 KN C. 75.23 KN D. 64.23 KN 5. What force acting at the pulley rim will crush the key? Answer: D
A. B. C. D.
143.37 KN 153.13 KN 165.39 KN 173.29 KN
45. A 76 mm bearing using oil with an absolute viscosity of 0.70 poise running at 500 rpm gives satisfactory operation with bearing pressure of 14 kg/cm2. The bearing clearance is 0.127 mm. 1. Determine the unit pressure at which the bearing should operate if the speed is changed to 600 rpm Answer: A A. 16.8 kg/cm2 B. 18.30 kg/cm2 C. 20.30 kg/cm2 D. 22.04 kg/cm2 2. If the bearing is given a total clearance of 0.076 mm, what change should be made in the oil? Answer: B A. 0.176 poise B. 0.251 poise C. 0.364 poise D. 0.472 poise
46. A Mitsubishi car transmission has two spur gears in mesh having velocity ratio of 1.4. The number of teeth in the driven gear is 36 and the diametrical pitch of 3. 1. Determine the number of teeth in the driver Answer: B A. 22 teeth B. 26 teeth C. 30 teeth D. 34 teeth 2. Determine the distance between centers Answer: C A. 6.23 in B. 8.30 in C. 10.34 in D. 12.09 in 3. What is the circular pitch? Answer: C A. 0.456 in B. 0.847 in C. 1.28 in D. 1.047 in 47. A flywheel weighing 910 kg has a radius of gyration of 1524 mm. The shaft journals are 304.8 mm in diameter and have a coefficient of friction of 0.06. After the wheel reaches 120 rpm, the driving force is withdrawn and the wheel slows to 60 rpm. 1. How much energy does the wheel loss? Answer: B A. 120,763 N-m B. 125,159 N-m
C. 130,458 N-m D. 145,609 N-m 2. What moment opposes the motion of the flywheel? Answer: D A. 65.34 N-m B. 70.34 N-m C. 75.45 N-m D. 81.63 N-m 48. A 2 ½ in (8.9 cm) diameter shaft is driven at 3600 rpm by a 400 hp (298.3 KW) motor. The shaft drives a 48 in (121.9 cm) diameter chain sprocket having an output efficiency of 85%. Determine: 1. Torque in the shaft Answer: A A. 7,003 in-lbs B. 7,197 in-lbs C. 7,563 in-lbs D. 8,408 in-lbs 2. The output force on the sprocket Answer: A A. 291.79 lbs B. 327.45 lbs C. 302.30 lbs D. 367.45 lbs 3. The power delivered by the sprocket Answer: C A. 320 hp B. 330 hp C. 340 hp D. 350 hp
