Dynamics of Rigid Bodies Sample Problems.docx

Dynamics of Rigid Bodies Sample Problems A race car accelerates from rest to a speed of of 287 km/h in 68 seconds seconds !hat is its a"erage acceleration#

1.

2 $he space sh%ttle %ndergoes an acceleration of &'( m/s 2 )o* fast is it tra"eling at the end of &&2 s#

' +an an ob,ect %nder constant acceleration acceleration come to rest and stay at rest# -.plain yo%r ans*er  0o% 0o% are in an ele"ator that is accelerating yo% %p*ard at && m/s2 )o* m%ch time till yo% are tra"eling at 11 m/s#

& $*o $*o cars tra"el in the same direction along a straight high*ay3 one at a constant speed of && mi/h and the other at 7 mi/h 4a5 Ass%ming that they start at the same point3 ho* m%ch sooner does the faster car arri"e at a destination 1 miles a*ay# 4b5 )o* far m%st m%st the faster faster car tra"el before it has a 1& min%te lead on the slo*er car#

4a5

$ime difference 4b5 1& min lead  ahead by distance e%al to that tra"eled by slo*er car in in 1& min min

rel speed

time to get ahead by 1'7& mi is

Distance tra"eled 6 A car car tra"eling in a straight line line has a "elocity of 9 & m/s at some instant instant After  s3 its "elocity is 9 8 m/s !hat is its a"erage acceleration d%ring this time inter"al#

7 A car car is tra"eling at 18 km/h3 km/h3 st%ck behind a slo*er car car :inally the road is clear and the car p%lls o"er to make make a pass $he dri"er stomps on the gas pedal and accelerates %p to a speed of 1'& km/h ;f it took '& s to reach this speed3 *hat is the a"erage acceleration#

8 A position position "s time time graph is sho*n to the right right Please analy
4c5 4d5  b = c3 4e5 4maybe5 a3 c3 d3 4maybe5 4maybe5 e

( 0o% 0o% *alk do*n the side*alk to the east for 8 min at a speed of 12 m/s 0o% 0o% reach a b%sy street and ha"e to stop stop 0o% 0o% remain at rest for 2 min%tes min%tes $he traffic dies do*n3 so yo% r%n across across the street at constant speed speed $he street is 12 m *ide and it takes yo% 1& s to cross it 0o% 0o% immediately slo* do*n to yo%r reg%lar 12 m/s *alk speed and proceed for 2 min 0o% 0o% s%ddenly disco"er that that yo%r pl%sh d%cky fell off yo%r backpack 0o% immediately immediately t%rn aro%nd and r%n back to the intersection yo% yo% ,%st crossed crossed 0o% 0o% r%n at a constant speed of 6& m/s >ake a distance "s time graph for yo%r motion