Dll Grade 8 First Grading - Final Copy

GRADES 1 to 12 Daily Lesson Log

School

Bilaran National HS

Teacher Teaching Date and Time

Grade Level

Grade 8

Learning Area

Science

Quarter

First

(Physics)

DAY: MONDAY I. OBJECTIVES A.

Content Standards

B.

Performance Standards



The learner demonstrates understanding of Newton’s three laws of motion and uniform circular motion.



The learner shall be able to develop a writer plan and implement a “Newton’s Olympics”.

(S8FE-Ia-15)

C.

 Learning Competencies / Objectives Write the LC code for each

Investigate the relationship between the amount of force applied and the mass of the object to the amount of change in the object’s motion.

Objectives: 1. Identify the forces acting on an object at rest. 2. Explain why objects stay at rest. Module I: FORCES AND MOTION

II. CONTENT

Lesson 1: BALANCED AND UNBALANCED FORCES

III. LEARNING RESOURCES A.

References 1.

Teacher's Guide Pages

pp. 5 - 8

2.

Learner's Materials Pages

pp. 3 - 6

3.

Textbook Pages

4.

Additional Materials from Learning Resource (LR) portal Lesson Guide Science 8 (First Quarter- pp. 1-5)

B.

Other Learning Resource

https://www.google.com.ph/search? pictures&oq=balanced+and+unbalanced+forces

IV. PROCEDURES Present the following statement in class and ask the students if they agree or disagree with them. Select two to three students per group to justify or explain their answer. A.

Reviewing previous lesson or presenting the new lesson

1. Force is needed to stop an object. 2. Force always results to motion. 3. Force can act even at a distance. 4. Objects have the tendency to remain at rest. 5. Objects have the tendency to resist change. Analyze the pictures (to be presented on the television screen) (can be printed)

B.

Establishing a purpose for the Lesson

C.

Presenting examples / instances of the new lesson

What have you observed on the picture presented?

The teacher will place a ball or any object on top of a table and ask:

D.

E.

Discussing new concepts and practicing new skills #1


a) Will this object move by itself? b) How can we make this object move? c) While it is moving, how can we make the object speed up or slow down? d) How can make it stop? e) How can we make it change its direction? Do the activity 1 Forces on object at rest in Lesson Guide Science 8 (First Quarter) pp. 5 or LM pp. 5- 6 Presentation of the output per group/ Processing: Analysis:

F.

Developing mastery (Leads to Formative Assessment 3)

Situation 1 1. Is the pen at rest or in motion? 2. Are there forces acting on the pen? If yes, draw the forces. You may use arrows to represent these forces. 3. What happens to the pen? What could have caused the pen’s motion? Situation 2 1. Is the book at rest or in motion? 2. Are there forces acting on the book? If yes, draw the forces acting on the book. 3. Did the book move? How will you make the book move?

G.

H.

Finding practical applications of concepts and skills in daily living

Making generalizations and abstractions about the lesson

Since friction is a resistance force that slows down or prevent motion, there are advantages and disadvantages that friction may do. How is friction important in: a. walking b. writing c. running vehicles 1. What is force? 2. What are some other forces that can cause something to move? 3. How does gravity affect object on earth? 4. What is a force that can cause an object to slow down or have little movement? 5. In your own words define friction. Multiple Choice: Read each statement carefully and write only the letter of the correct answer. 1. A book is at rest on top of a table. Which of the following is correct? A. There is no force acting on the book. B. The book has no inertia. C. There is no force acting on the table. *D. The book is in equilibrium.

I.

Evaluating Learning

2. Which of the following situations involves friction? A. A bicycle rolling down a hill B. A baseball player sliding into 2nd base C. A diver falling through the air to a pool *D. All of the above experience some friction. 3. What is gravity? A. Newton’s first law B. The force that objects exert on each other because of their masses *C The downward pull on the Earth D. The friction that an object has put on it 4. Which is the best example of gravity?

A. A car hits a tree, and its motion stops B. A breeze blows, and a sailboat moves C. A book is pushed, and it moves across the table *D. A person drops a ball, and it falls to the ground 5. How does Earth ‘s gravity affect objects near Earth? A. It pushes them away. *B. It pulls them in C. It makes them larger. D. It makes them move faster. Additional activities for application or remediation

J.

V. REMARKS VI. REFLECTION A. B.

C.

No. of learners who earned 80% in the evaluation No. of learners who require additional activities for remediation who scored below 80% Did the remedial lessons work? No. of learners who have caught up with the lesson

D.

No. of learners who continue to require remediation

E.

Which of my teaching strategies worked well? Why did these worked?

F.

What difficulties did I encounter which my principal or supervisor can help me solve?

G.

What innovation or localized materials did I Use or discover which I wish to share with other teachers?

Ask the students to write situation/ examples where the presence of other forces are beneficial.


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)

DAY: I. OBJECTIVES A.

Content Standards

The learner demonstrates understanding of Newton’ three laws of motion and uniform circular motion.

B.


The learner shall be able to develop a writer plan and implement a “Newton’s Olympics”. (S8FE-Ia-16)

C.


Infer that when a body exerts a force on another, an equal amount of force is exerted back on it.

Objectives: 1. Describe the conditions when two forces balance 2. Explain the effect of balanced forces on the state of motion of an object.

II. CONTENT

Module I: FORCE AND MOTION Lesson 2: BALANCED AND UNBALANCED FORCES


B.

References 1.


pp. 5 - 8

2.


pp. 3 - 6

3.

Textbook Pages

4.

Additional Materials from Learning Resource (LR) portal


EASE Physics, Module 10. Lesson 3

Lesson Guide Science 8 (First Quarter- pp. 8-10)

IV. PROCEDURES A. Reviewing previous lesson or presenting the new lesson

What are the forces acting on an object at rest? What are examples of balanced forces? Students were given time to watch a short video clip about balanced and unbalanced forces ( www.youtube.com/watch?v=HEJOybRxclk)

B.


C.


Give reaction to the video presented

D.


Do the activity 2 in Lesson Guide Science 8 (First Quarter) pp. 8 – 9 or Learners’ Module pp. 7


1. When the cardboard is at rest, how do the magnitudes and directions of the pair of forces acting on it compare? 2. If you draw the lines of action of all the forces acting on the board and extend the lines, what will you get?


Discuss the answers in the activity

E.

F.

Study the given pictures below and describe the forces involved.

G.

Finding practical applications of concepts and skills in daily living The following ideas must be realized by the students:

H.


If two forces acting on an object are equal in magnitude but opposite in direction, they are considered as balanced forces. These forces must lie along the same line. 

If the forces acting on an object are balanced, the object either stays at rest or continues to move at constant velocity.



If the forces acting on an object are unbalanced, the motion of the object will change.

Direction: Read each statement carefully and write the letter of the correct answer. 1. ______________ refers to when a force is equal and opposite. *A. balanced force B. unbalanced force C. magnitude D. friction 2.When one force in a pair is greater than the other, we call this: A. balanced force *B. unbalanced force C. magnitude D. friction

I.

Evaluating Learning

3. If two forces are acting on an object they are equal in magnitude A. and equal in direction *B. and in opposite direction C. cancel each other D. none of the above For question no 4 and 5 refer to the diagram below Two tugboats are moving a barge. Tugboat A exerts a force of 3000 N to the left. Tugboat B exerts a force of 5000N in the same direction.

a. Draw arrows showing the individual forces of the tugboats in #1. b. Are the forces balanced or unbalanced? ______________ c. In what direction will the barge move? ________________ J.

Additional activities for application or remediation


No. of learners who earned 80% in the evaluation No. of learners who require additional activities for remediation who scored below 80%

1. define what inertia is. 2. What is stated in the first law of motion?

C.

Did the remedial lessons work? No. of learners who have caught up with the lesson

D.


E.


F.


G.



School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.


C. Learning Competencies / Objectives Write the LC code for each

The learners demonstrate an understanding of Newton’s three laws of motion and uniform circular motion. The learners shall be able to develop a written plan and implement a “Newton’s Olympic” S8FE –Ib-17  Demonstrate how a body responds to changes in motion. Objectives: 1. State the Law of Inertia 2. Relate inertia to mass 3. Cite situations where the law of inertia applies. Module I: FORCE AND MOTION Lesson 3: NEWTON’S THREE LAWS OF MOTION The Law of Inertia

II. CONTENT III. LEARNING RESOURCES A.

B.

References 1.


pp 10-11

2.


pp. 10 -12

3.

Textbook Pages

4.



EASE Physics, Module 10. Lesson 3 Lesson Guide G8 First Quarter pp. 11 - 12

IV. PROCEDURES A.


Differentiating balanced and unbalanced forces Let the students guess the word being defined by solving the jumbled letters. 1. It refers to the amount of matter an object has.

A

S

M

S

2. It is a push or pull upon an object resulting from the object’s interaction with another object.

R B.

E

C

F

O

Establishing a purpose for the Lesson 3. An action or process of moving or of changing place or position.

T

I

N

O

O

M

4. It is the resistance of any physical object to any change in its state of motion.

I

A

E

R

I

T

N

Are those set of words familiar to you? C.


What ideas came in your mind when you met those words we had unscrambled?

D. E.

Discussing new concepts and practicing new skills #1 Discussing new concepts and practicing new skills #2

The learners will analyze the picture of the two wrestlers by comparing their masses and relating the concept of mass to inertia. (see figure on pp. 11 LG grade 8 First Quarter)

Do the activity on Inertia (A and B) Learners’ Module pp. 11 – 12 Questions: PART A. 1. What happens when you slowly pulled the cardboard? Explain.

F.


2. What happens when you flipped the cardboard? Explain. PART B. 1. What happen to the remaining books after one book was pulled? Why is this so? 2. Relate your observation to the concept of inertia. Use the following examples to explain how Newton's first law occurs in everyday events: a) car suddenly stops and you strain against the seat belt.

G.


b) when riding a horse, the horse suddenly stops and you fly over its head. c) the magician pulls the tablecloth out from under a table full of dishes. d) the difficulty of pushing a dead car. e) car turns left and you appear to slide to the right.

H.


Newton's first law states that an object at rest will stay at rest or an object in motion will stay in motion and travel in straight line, as long as no external net force acts on it. The object will change its state of motion only if there is unbalanced or net force acting upon it. Inertia is measured in terms of mass. An object having greater mass has greater inertia Choose the best answer. Write letter only. 1. According to Newton's First Law of Motion, A. an object in motion eventually comes to a stop. B. an object at rest eventually begins to move. C. an object at rest always remains at rest. *D. an object at rest remains at rest unless acted upon by a net force.

I.

Evaluating Learning

2. The greater the mass of an object, A. the easier the object starts moving. B. the more space it takes up. *C. the greater its inertia. D. the more balanced it is. 3. The tendency of an object to resist any change in its motion is known as A. balance. B. force *C. inertia. D. mass. 4. Mass of the object is quantitative measure of its inertia stated law is newton's *A. first law B. second law C. third law

D. fourth law 5. Which of these best describes the concept of inertia? A. A force that attracts objects with mass B. The tendency of an object to float in water C. A force created when surfaces are in contact *D. The tendency of an object to resist a change in motion Write your answer in your notebook. J.



C.


D.


E.


F.


G.


1. Define acceleration. 2. What is stated in the second law of motion?


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.


The learners demonstrate an understanding of Newton’s three laws of motion and uniform circular motion.

The learner shall be able to develop a writer plan and implement a “Newton’s Olympics”. S8FE –Ib-17  Demonstrate how a body responds to changes in motion.

C.

Learning Competencies / Objectives Write the LC code for each

II. CONTENT

Objectives: 1. State the Law of Acceleration. 2. Discuss the relationship between net force on an object and its acceleration, and between the mass of an object and its acceleration. 3. Cite some applications of this law in our daily life. Module I: FORCE AND MOTION Lesson 4: THREE LAWS OF MOTION Law of Acceleration


B.

References 1.


pp. 11- 12

2.


pp. 15 - 16

3.

Textbook Pages

4.




IV. PROCEDURES A.


What is inertia? How is the law of inertia related to mass? Study the picture. Can a man pushes the car? How much force is needed by the man to push the car?

B.


The teacher will present two balls of different masses. Then ask the students which of the two balls will accelerates faster? Why? C.

Presenting examples / instances of the new lesson tennis ball

D.


bowling ball

1. Differentiate the two balls in terms of mass. Which has the greater mass? 2. If equal amount of force will be applied in the two balls, then which will accelerates faster?

E.


Do the activity on The Law of Acceleration, Lesson Guide G8 First Quarter pp.17 - 19


A. 1. What variable/s is/are said to be constant in the activity? 2. What is the effect of varying the amount of force on the acceleration of the cart? 3. What relationship exists between the force and acceleration when the mass of the cart is kept constant? B. 1. What variable/s is/are said to be constant in the activity? 2. What is the effect of varying the mass on the acceleration of the cart? 3. What relationship exists between the mass and acceleration when the force is kept constant?

F.

G. Finding practical applications of concepts and skills in daily living

H.


Present the statement in the class “ You may be bigger but I am faster” a. How does this line illustrate Newton’s Second Law of Motion? b. How is the statement related to mass and acceleration? 1. State the second law of motion 2. How is acceleration related to the object’s mass and the amount of force exerted? 3. What relationship exists between acceleration and force; force and mass? 4. How is the second law of motion applied to everyday occurrences? Direction: Read each statement carefully and write the letter of the best answer. 1. Which among the Newton’s Laws of Motion states that force equals mass times acceleration? A. 3rd Law B. 1st Law *C. 2nd Law D. all of the above 2. According to Newton's 2nd Law of Motion, force equals – A. mass divided by acceleration B. mass plus acceleration C. mass subtract acceleration *D. mass times acceleration

I.

Evaluating Learning

3. How does the acceleration of an object change in relation to its mass? It is _________. A. directly proportional *B. inversely proportional C. acceleration doesn’t depend on mass at all D. neither A or B 4. Suppose a cart is being moved by a force. If suddenly a load is dumped into the cart so that the cart’s mass doubles, what happens to the cart’s acceleration? A. It quadruples. B. It doubles. *C. It halves. D. It quarters. 5. Which will accelerate faster? A. a 1000 tons truck B. a fully loaded bus C. an overloaded jeepney *D. a race car

J.




Explain how mass differs from weight.

C.


D. No. of learners who continue to require remediation E.


F.


G.



School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.



The learner shall be able to develop a writer plan and implement a “Newton’s Olympics”. S8FE –Ib-17  Demonstrate how a body responds to changes in motion.


Objective: Solve problems involving the interrelationships of net force, mass and acceleration Module I: FORCE AND MOTION Lesson 5: THREE LAWS OF MOTION The Law of Acceleration: Computation


B.

References 1.


pp. 13- 16

2.


pp. 15 - 17

3.

Textbook Pages

4.



Physics ( Science and Technology Textbook- NPSBE Edition) EASE Physics, Module 10. Lesson 3 Lesson Guide G8 First Quarter pp. 20 - 22

IV. PROCEDURES A.


Ask the students to restate the second law into a simple statement. Derivation of Formula: From the statement that acceleration is directly proportional to force at constant mass. Mathematically a=kF

where nK

=

mass (eq. 1)

Acceleration also varies with mass. As the mass of the object increases with the same amount of force applied, its acceleration decreases thus: a= k(1/m) where K=net force (eq.2) B.

Establishing a purpose for the Lesson Combining the two equations, we have a α F and a α 1/m Therefore a α F/m Mathematically, a = F/m where a= acceleration m= mass F= force

C.


Give and discuss at least two examples of situation/problems on the Law of Acceleration

1. A huge stone is pushed with 30 N of force. If there is only 5N of friction and the stone’s mass is 88 kg. What is the acceleration of the table? 2. A car is being towed. If its mass is 1750 kg and it accelerated at 5m/s2, how much netforce is involved? D.

E.

F.

G.

Discussing new concepts and practicing new skills #1 Discussing new concepts and practicing new skills #2 Developing mastery (Leads to Formative Assessment 3) Finding practical applications of concepts and skills in daily living

Do the exercise in Lesson Guide G8 First Quarter pp 21 (choose items which will be solved individually/ in group) Presentation of the outcomes.

Discuss the answers in the exercise given. Engineers at the Johnson Space Center must determine the net force needed for a rocket to achieve an acceleration of 70 m/s2 . If the mass of the rocket is 45,000 kg, how much net force must the rocket develop. Mathematically, second law of motion can be expressed: A = F/m F = ma M = F/a

H.


If the unit of Fnet ( Fn) is in Newton, mass(m) is in kilogram (kg) and acceleration is in meter per second/second (m/s2) Since force is a vector quantity and mass is a scalar quantity ,acceleration is also a vector quantity where acceleration follows the direction of the net force The unit of of acceleration can be derived also from N/kg, since 1N = 1 kg.m/s2 therefore, N/kg = kg.m/s2 /kg = m/s2 Direction: Solve problems involving the Law of acceleration then write the letter of the correct answer. 1. What is the mass of a truck if it produces a force of 14,000N while accelerating at a rate of 5 m/s2 ? A. 280 kg C. 70,000kg

*B. 2800kg D. 7000kg

2. Which is the correct unit of acceleration? A. m/s *B. m/s2 C. kg.m/s I.

Evaluating Learning

3.

D. kg.m/N

Suppose that a sled is accelerating at a rate of 2m/s2 . If the net force is tripled and the mass is halved, what then is the new acceleration of the sled? A. decrease by half B. doubled *C. tripled D. quadrupled

4. Suppose a ball of mass 0.60 kg is hit with a force of 12 N. Its acceleration will be: *A. 20 m/s2 B. 40 m/s2 C. 10 m/s2 D. 20 m/s 5. If the ball in question no. 4 is increased by 24 N, what is the increased in acceleration? A. 20 m/s2 B. 30 m/s2 *C. 4 0 m/s2 D. 50 m/s2 J.


V. REMARKS VI. REFLECTION

Give additional information regarding: balance and un balance forces>

A. B.

C.


D.


E.


F.


G.



School

Grade Level

Grade 8


Learning Area

Science

Quarter

First

(Physics)


Content Standards

B.



The learner shall be able to develop a writer plan and implement a “Newton’s Olympics”. S8FE –Ib-17  Demonstrate how a body responds to changes in motion.  Infer that when a body exerts a force on another, an equal amount of force is exerted back on it.

C.


Objectives: 1. State Newton’s Third Law of Motion 2. Compare the two interacting forces in terms of magnitudes and directions. 3. Identify the action and reaction forces in the given situations. Module I: FORCE AND MOTION Lesson 6: THREE LAWS OF MOTION The Law of Interaction


B.

References 1.


pp. 13 - 16

2.


pp. 18 - 19

3.

Textbook Pages

4.




IV. PROCEDURES A.


B.


Differentiate first law of motion to the second law of motion

Imagine yourself leaning against a tree same with the picture below. Did you topple over while you are still in contact with the tree? Why or why not!

C.


D.


E.

Do the activity in Lesson Guide G8 First Quarter pp 23 - 24 or Learners’ Module pp 19 - 20 Analysis: 1. What is the reading on your balance and that of your partner?

What do these values represent? 2. How do you compare the direction of your partner’s and your force? 3. What is the reading on your balance and that of your partner? 4. How do you explain your observation? 5. What is the reading in each balance? 6. Compare the direction of the forces exerted on the two ends of the connected spring balance. Analyze the situations below by identifying the pairs of forces acting on the objects.

F.


Situation 1

G.


Situation 2

The class will be divided into small group. Each group is assigned to 1 of the situations listed below. They will be given 1 minute to draw/paint the scene and another 30 seconds to position themselves. Challenge the students to guess the picture of the other group then ask them to identify the action-reaction forces present. a. walking b. a mango fell due to gravity c. a man pedals a bicycle d. a person lying down in the emergency room

H.


1. Based from the above activity state operationally the law of interaction. 2. Why do forces come in pairs? 3. Explain the condition on how to forces are equal in magnitude and acting in opposite direction. Direction: Read each sentence carefully and write the letter of the correct answer. 1. As a 500 N lady sits on the floor, the floor exerts a force on her equal to______________. A. 1000 N *B. 500 N C. 250 N D. 50 N 2. According to Newton's Third Law of Motion, when a hammer strikes and exerts a force on a nail, the nail A. creates a balanced force. B. disappears into the wood. C. moves at a constant speed. * D. exerts and equal and opposite force back on the hammer.

I.

Evaluating Learning

3. Pick the best example of Newton's Third Law in action. A. A rocket taking off from earth which pushes gases in one direction and the rocket in the other. *B. A rocket sitting on the ground preparing for take-off but it needs an outside force to overcome its inertia of a nonmoving object. C. A rocket that is accelerating through space and exerts a great amount of force because its mass and acceleration is so large. D. Both b and c. 4. When a teacher stands at the front of the class, the force of gravity pulls her toward the ground. The ground pushes back with an equal and opposite force. This is an example of which of Newton's Laws of Motion? A. Law of Inertia

B. Law of Acceleration *C. Law of Interaction D. Law of Universal Gravitation 5. For every action there is an equal and opposite reaction. This is a statement of A. Newton's First Law of Motion. B. Newton's Second Law of Motion. *C. Newton's Third Law of Motion. D. Newton's Law of Action. J.



C.


D.


E.


F.


G.


Design and implement an experiment that will verify Newton’s Law of Motion.


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First


Content Standards

B.


C.


The learner demonstrates understanding of Newton’s three laws of motion and uniform circular motion. The learner shall be able to develop a writer plan and implement a “Newton’s Olympics”. S8FE –Ib-18 /19  Relate the laws of motion to bodies in uniform circular motion.  Infer that circular motion requires the application of constant force directed toward the center of the circle. Objectives: 1. Define circular motion 2. Identify the factors affecting circular motion. 3. Relate circular motion and Newton’s Law of Motion.

II. CONTENT

Module I: FORCES AND MOTION Lesson 7: Circular Motion And Newton’s Second Law Of Motion


B.

References 1.


pp. 13 - 16

2.


pp. 18 - 19

3.

Textbook Pages

4.



Lesson Guide in Grade 8 – First Quarter pp. 26- 28

IV. PROCEDURES A.


Recall the second law of motion. How is the acceleration of the body being affected by its mass. Try to whirl a stone tied to a string horizontally above your head. Then observe what happen if you release the object. How does it travel after release?

B.


Why doesn’t the released stone move outwards, in the direction in which it pulled? C.


D.

Discussing new concepts and practicing

How does gravity make satellites revolve at a constant speed? What will happen if all of a sudden, the earth loses its gravitational pull on the satellites?

new skills #1

E.


F.


G.


Let the students watch the video on circular motion and its relationship to the second law of motion. www.youtube.com/watch?v=EPfT31qFmGY From the video clip presented, how does circular motion related to the laws of motion. Discuss it in terms of change in velocity

Why are accidents more frequent along a curve path? According to Newton’s second law of motion acceleration is produced by a net force. The net force and the acceleration must be in the same direction. From the second law, F = m a. If applied to uniform motion, the acceleration becomes the centripetal acceleration and the net force. Since it is also directed towards the axis of rotation, it becomes the centripetal force. Centripetal force can be defined as the net force on an object that maintains the object’s circular path and is directed towards the center of the circular path. The formula in calculating for the centripetal force is Fc = mac , where: Fc = centripetal force (N) m = mass (kg) a = centripetal acceleration (m/s2)

H.


If using the tangential speed and angular speed the equation can be rewritten as: Fc = mv2 / r or mrώ Where: V = tangential speed ( m/s ) r = radius ( m ) ώ = angular speed (rad/s) The centripetal force is the force that maintains the circular path of the objects. If the centripetal force is zero, the object will move in a straight line.

Direction: read the questions below and select the letter of the best answer. 1. What made the stone in the previous activity move in circular path? *A. The central force enables the stone to stay in its path. B. The gravity enables the stone to move in circular path. C. The force of attraction make its stay in place. D. The string made the stone to whirl in circular path. 2. This is a force that keeps an object move in circular path. A. frictional force *B. centripetal force C. gravitational force D. attractive force I.

Evaluating Learning

3. All are examples of events/ activities in our daily life which shows or illustrates the need of a central force. Which is not included in the group? A. merry-go-round B. banking on curved C. satellite moon *D. cyclist on the straight road 4. In what direction does an object fly if the force giving its centripetal acceleration suddenly disappear? A. The object continuously moves in circular motion, *B. The object moves in straight line at constant speed. C. The object changes its velocity in a straight path. D. Hard to determine where the object goes. 5. When a car turns around a curve and its speed doubled, what happens to the force between the road and its wheels?

A. It doubles *B. It increases four times C. It is reduced to one-half D. It is reduced to one-fourth

Journal entry: Think and look for words and ideas that relate to the word on the box. Write the words and ideas on the lines around the box. J.



C.


D.


E.


F.


G.


CENTRIPETAL FORCE


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First ( Physics)

DAY: I. OBJECTIVES

A.

Content Standards

B.


The learner demonstrates understanding of work using constant force, power, gravitational potential energy, kinetic energy, and elastic potential energy

(S8FE-Ic-20)

C.


Identify situations in which work is done and in which no work is done

Objectives: 1.Define work scientifically 2.Identify situations in which work is done and in which no work is done.

II. CONTENT

MODULE II: WORK, POWER AND ENERGY Lesson 8: WHAT IS WORK?


B.

References 1.


18-19

2.


21-23

3.

Textbook Pages

4.



Lesson Guide Grade 8 First Quarter, pp. 29-30

IV. PROCEDURES A.


B.


State the Second Law of Motion

Ask the students if they know the meaning of work. Emphasize to them that the meaning /definition of work and the one that we use in Science are quite different from each other. Simple Demonstration: Ask three students to demonstrate in the class the following actions/tasks:

C.

D.



a. Student 1 pushes the blackboard. b. Student 2 pulls a chair from one end of the room to the other end. c. Student 3 pulls a chair then return it to its original place.

From the three demonstrations, which activity showed that work is done or no work done? Explain.

E.


Do the Activity on Is there work done? Lesson Guide Grade 8 First Quarter pp. 29-30 Analysis: 1. Which of the four situations demonstrated or showed that work is done? Why?

F.


2. Why do you think situation number 3 did not show that no work is done? Why? 3. What is the effect of the force the object? 4. How will you relate the force and the direction of the motion? 5. When can we say that work is done? Agree or Disagree !!! Ask the students to take a stand by showing thumbs up or thumbs down sign with the following statements.

G.


H.


1. Work does not necessarily mean physical labor. 2. If there is displacement in the same direction of the force then there is work automatically. 3. Work done at a very limited time frame means there is high power output. 4. If there is no force exerted, there won’t be any work output. 5. If force and distance move at an angle there is work one. Work is present when the force exerted causes an object to have a displacement in the same direction of the force. (You may use the picture on the lesson guide) Identify situations in which work is done and in which no work is done. Write W if the situation shows work and NW if no work.

I.

Evaluating Learning

J.


V. REMARKS VI. REFLECTION A.

No. of learners who earned 80% in the evaluation

B.

No. of learners who require additional activities for remediation who scored below 80%

C.


D.


E.


F.


1. Lifting a box from the floor. 2. Pushing against the wall. 3. Pushing a box along the floor. 4. Carrying a bag of grocery 5. Raising a flag during the flag ceremony How do you measure the amount of work done? Illustrate how to calculate work and determine the corresponding units work.

G.



School

Grade Level

Grade 8


Learning Area

Science

Quarter

First ( Physics)

DAY: I. OBJECTIVES

A.

Content Standards

B.



(S8FE-Ic-20)

C.



Objective; Calculate the amount of work done using appropriate units. Module Ii: WORK, POWER AND ENERGY Lesson 9: CALCULATING WORK


B.

References 1.


2.


3.

Textbook Pages

4.



19 – 20 24 – 25


IV. PROCEDURES A.


When do we say that work is done? Students will watch a short video clip on how to calculate the amount of work done on the object.

B.

C.

D.




(please follow the link for the video clip on work www.youtube.com/watch?v=hQKYb7P5vwA) Example of situational problems on work 1. A box is dragged horizontally across a floor by a 100 N force acting parallel to the floor. What is the work done by the force in moving it through a distance of 8 m? Do the Activity on Calculating Work, Lesson Guide Grade 8 First Quarter pp. 33-34

Work problems to be solved by pair

1. A body moves through a distance of 4 m while a force F of 12 Newton acts on it. What is the work done by the force on the body?

E.

2.Two men exerted a force of 1080 N to push the car 218 m to the nearest fuel station. Determine the work done on the car.

F.


Discuss the answer on the given exercises Analyze the picture, Do you think that the man climbing upstairs demonstrate or performs work? Why?

G.


Work is said to be done when a body undergoes displacement. It is denoted by W. Work Formula is given by W = F . d H.


where : F = force applied and d = displacement. Work formula is used to calculate work done, force or displacement in any problems. It is given in N-m. Direction: Read each statement carefully and write the letter of the correct answer. 1. How much work is required to lift a 2 kg mass to a height of 10 meters? A. 5 J B. 20 J *C. !00 J D. 200 J 2. A garden tractor drags a plow with the force of 500 N in a distance of 10 meters in 20 seconds. How much work is done? A. 0.25 J B. 1000 J C. 2599 J *D. 5000J 3. One joule is equivalent to: A. 1 N.m3 B. 1 kg.m3

I.

Evaluating Learning

C.1 watt2 .N

*D. 1 kg.m2 /s2

4. Which of the following 10 N forces acting over 10 m would produce the most work?

30 degrees A

45 degrees C

45 degrees B

Horizontal *D

5. Students A and B run up the same flight of stairs. 

Both students run up the stairs at constant velocities.

 

Student A takes twice as long as student B to climb the stairs. Student A weighs twice as much as student B

I. Student A develops more power than student B. II. Student B does more work than student A. III. The change in potential energy of student A is twice that of student B. A. I only C. I and II only J.




B.


C.


D.


E.


F.


G.


*B. III only D. I and III only

Why is work considered a method of transferring energy?


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First ( Physics)

DAY: I. OBJECTIVES

A.

Content Standards

B.



(S8FE-Ic-20)

C.



Objectives: 1.Describe the energy changes when energy is transferred from one body to another. 2.Give examples of how energy is transferred

II. CONTENT

Module II: WORK, POWER AND ENERGY Lesson 10: Work Is A Method Of Transferring Energy


B.

References 1.


20-21

2.


25-26

3.

Textbook Pages

4.



Lesson Guide Grade 8 First Quarter pp 37-38

IV. PROCEDURES A.

B.



C.


D.

Discussing new concepts and practicing

How will you compute the amount of work done by an object? Energy enable us to do work. It is likened to money. Having a lot of energy is like having plenty of money. But having money is not enough to do useful things. Money should be handed over to another person so it can do something. Energy is also like this. It needs to be transferred to another body so it can do something useful. Examples of situation that shows transfer of energy: 1.When you push a book across the table, the energy from your moving arm is transferred from your body to the book, causing the book to move. 2. Fingers hitting piano keys transfer energy from the player’s hand to the keys.

new skills #1

Do the Activity - Lesson Guide Grade 8 First Quarter pp 37-38 Analysis: 1. Is there work done on the ball?

E. Discussing new concepts and practicing new skills #2

2. What can a moving ball do when it interacts with other object? 3. What happens to the energy of the ball (doing the work) and the bottle ( on which work is done)? Explain your answer.

F.


G.


H.


Discuss the answers in the given activity Cite other examples of energy transfer in your daily life situations.

When energy is transferred, one body loses energy, where as another gains it.Work is a method of energy transfer. When a body does work, it loses energy. The body on which work is done gains energy. Examples of energy transfer are: a. A spring vibrates after being stretched b. A bicycle going uphill, which stops. Direction: Choose the letter of the correct answer. 1. In which situation is there NO work done in the system? a. A monkey climbing a tree b. A person in an ascending elevator c. A weight lifter lifting a barbell in the air d. A stone whirled around the horizontal circle 2. Describe the energy changes that take place when the ball is thrown upward. a. Potential to Kinetic b. Kinetic to Potential c. Both a and b d. Cannot be determined

I.

Evaluating Learning

3. What happens to energy when it is transferred from one body to another? a. Energy is gained. b. Energy is destroyed. c. It loses energy. d. Both a and c For numbers 4 and 5, Show complete solutions. 4. A ball with mass of 2 kg is dropped from a height of 60 m. What is the potential energy of the ball? Assume that the reference position is the ground. 5. A book weighs 5.0 newtons when it is raised 1.5 meters. Calculate its increase in potential energy.

J.




Explain how work is related to power.

No. of learners who require additional activities for remediation who scored below 80% C.


D.


E.


F.


G.



School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)

DAY: Tuesday I. OBJECTIVES

A.

Content Standards

B.



(S8FE-Ic-21)  C.


Describe how work is related to power and energy

Objectives: 1. Describe how work is related to power and energy. 2. Compute for your power output in walking or running up a flight of stairs Module II: WORK, ENERGY AND POWER Lesson 11: HOW POWER-FUL AM I?


B.

References 1.


2.


3.

Textbook Pages

4.



23-24 34-35


IV. PROCEDURES A.


Differentiate potential form kinetic energy Video Presentation

B.


Showing a short video clip about sport Triathlon (www.youtube.com/watch?v=wxtR9hf39Ug)

C.

D.


Discussing new concepts and practicing new skills #1 Discussing new concepts and practicing

Ask the students to explain if there is work done by the athletes participating in the said event. Ask them also if they use energy. Do the Activity on How POWER-ful am I, Lesson Guide Grade 8 First Quarter, pp. 40-41

new skills #2 E.

Name

Weight (N)

Height of stairs (m)

Time taken to climb the stairs ( s )

Energy Expended (J)

Power ( J/s )

Q1. Who among the group members had the highest power output? Q2. What is the highest power output? Q3. Who among the group members had the lowest power output? Q4. What is the lowest power output? Q5. What can you say about the work done by each member of the group? Q6. Did each member perform the same amount of work in climbing the stairs? Q7. What factor/s determined the highest/lowest power output? F.


Discuss the answers in the given activity Your opinion here!

G.


If you were be given a chance to be the leader of the our country, how would you exercise your power of authority? Power provides a measure of both the amount of work done or the amount of energy expended and the time it takes to do it. If you do a physical task quickly you have more power than when you do the same task slowly.

H.


In science, power is defined as the rate at which work is done or the rate at which energy is expended, or is transferred, or transformed. In equation, Power = work/time or Power = energy/time What is the SI unit of power? Since the SI unit of work is joule and the SI unit of time is second, the SI unit of power is Joule/second. This is given a special name, watt, in honor of James Watt. So, 1 watt (W) = 1 joule (J)/second (s) Direction: Choose the letter of the correct answer.

I.

Evaluating Learning

1. Which of the following statements indicates the best way to increase power? *A. increase the amount of work done in a given amount of time, or do a given amount of work in less time B. increase the amount of work done in a given amount of time, or do a given amount of work in more time. C. decrease the amount of work done in a given amount of time, or do a given amount of work in less time . D. decrease the amount of work done in a given amount of time, or do a given amount of work in more time. 2. What does the power of a machine measures? A. the work it does *B. its rate of doing work C. the force it produces D. its strength 3. A girl carries a heavy suitcase quickly up a flight of stairs. A

boy of the same weight carries the same suitcase slowly up the flight of stairs. Which statement is true? A. The girl did less work and had less power than the boy. B. The girl had less power than the boy. C. The girl did more work and had more power than the boy. *D. The girl had more power than the boy

4. What is the power develop by a jumbo jet that cruises at 200 m/s when the thrust of its engine is 100,000 N? A. 20,000 W B. 200,000W C. 20,000,000W D. 2000 W 5. The following the units to express power. Which is not included? A. N.m/s B. J/s C. watt D. N.m/s2 1. What are the different forms energy? J.




B.


C.


D.


E.


F.


G.


2. What are the types of mechanical energy?


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First ( Physics)

DAY: Tuesday I. OBJECTIVES

A.

Content Standards

B.


1. Define kinetic energy. 2.Relate the speed and position of object to the amount of energy possessed by a body. 3. Calculate the kinetic energy of a moving body. The learner demonstrates understanding of work using constant force, power, gravitational potential energy, kinetic energy, and elastic potential energy

(S8FE-Id--22) (S8FE-Id-23)

C.

  Learning Competencies / Objectives Write the LC code for each

Differentiate potential and kinetic energy. Relate speed and position of object to the amount of energy possessed by a body.

Objectives: 1. Define kinetic energy. 2.Relate the speed and position of object to the amount of energy possessed by a body. 3. Calculate the kinetic energy of a moving body Module II: WORK, POWER AND ENERGY Lesson 12: KINETIC ENERGY


B.

References 1.


21

2.


26-28

3.

Textbook Pages

4.



Lesson Guide Grade 8 First Quarter, pp 43-44

IV. PROCEDURES A.


How will you define power? Picture Analysis:

B.


The student will look at the picture presented by the teacher.

C.


What kind of energy does the boy possess? Explain your answer.

D.


Do the Activity on Exploring kinetic energy with ramps, Lesson Guide Grade 8 First Quarter, pp 43-44


F.


Analysis: 1. Which car will run fastest? Why do you think so? 2. How does the amount of energy possessed by each car affect its speed?

Discuss the answers in the activity given. How do kinetic energy applies to everyday life?

G.


1.a running roller coaster 2.your jaw when you are chewing 3.when playing billiard, the energy is transferred from the stick to a ball 4.A Slinky moving down a set of steps 5.Snow skis gliding down the mountain 6.Gas molecules moving around in a room The kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. If the masses {weights} are equal, the body with the greatest velocity {speed} would have the highest kinetic energy. If the velocities are equal, the body with the greatest mass would have the highest kinetic energy. The kinetic energy of an object is given by the equation:

H.


KE = 1/2mv2, where m is the mass of the object and v is its velocity. The kinetic energy is proportional to the mass of the object. According to Newton’s second law, F = ma, an object is accelerated with a constant acceleration of a constant net force is exerted on it. The work done on object is given by: W = F. d. Thus the work done is W = (ma)d. Assume the object was originally at rest, Vi = 0. As it accelerates, v2 = 2ad, or d = v2 / 2a, since a is constant. Therefore: W = mad = ma (v2 / 2a) = 1/2mv2 Assessment:

I.

Evaluating Learning

Tell whether each statement is true or false:

1. When work that is done on a body increases its velocity, then, there is an increase in the kinetic energy of the body. 2. The kinetic energy of a more massive object at rest is greater than that of a less massive moving object. 3. If the velocity of a moving object is doubled, its kinetic energy is also doubled. 4. The unit of kinetic energy is the same as the unit of work. 5. The unit kg m2/s2 is also a unit of energy. J.




B.


C.


D.


E.


F.


G.


What is potential energy?


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)

DAY: I. OBJECTIVES

A.

Content Standards

B.


The learner demonstrates understanding of work using constant force power, gravitational potential energy, kinetic energy, and elastic potential energy

(S8FE-Id--22) (S8FE-Id-23)

C.

  Learning Competencies / Objectives Write the LC code for each

Differentiate potential and kinetic energy. Relate speed and position of object to the amount of energy possessed by a body.

Objectives: 1. State the meaning of potential energy. 2. Relate potential energy to work 3. Calculate the change in potential energy of a body

Module II : WORK, POWER AND ENERGY Lesson 13: POTENTIAL ENERGY

II. CONTENT


B.

References 1.


2.


3.

Textbook Pages

4.



21-22 28-33

Lesson Guide Grade 8 First Quarter, pp 47-49

IV. PROCEDURES A.

B.


What is kinetic energy? Give the formula of kinetic energy


Present the video to the class and have them watch the video about the roller coaster ride

(https://www.youtube.com/watch?v=JFNKyi_lzyg) C. Presenting examples / instances of the new lesson D. Discussing new concepts and practicing new skills #1

Do Activity on Rolling Toy - Lesson Guide Grade 8 First Quarter pp 47-49

Analysis:

E.

F.

After watching the video let the students brainstorm on what they have viewed. Ask them: “What science concepts are involved in the roller coaster? “Today, we will deal more on the energy possessed by the roller coaster.”


Q1. What happens to the toy? Q2. What kind of energy is ‘stored’ in the rubber band? Q3. What kind of energy does a rolling toy have? Q4. What transformation of energy happens in a rolling toy?


Discuss the answers in the activity given

G. Actor and actress of the day Finding practical applications of concepts and skills in daily living

Ask 5 learners to give example of potential energy then each them will act the given situations. The audience will determine if the action taken by the actor/actress is example of potential energy.

Potential energy, or stored energy, is the ability of a system to do work due to its position or internal structure. For example, gravitational potential energy is a stored energy determined by an object's position in a gravitational field while elastic potential energy is the energy stored in a spring.

H.

As a form of energy, the SI units for potential energy are the joule (J) or Newton-meter (N*m). Making generalizations and abstractions about the lesson

The change in the object’s gravitational potential energy is the work done in raising it to that height. Since the work done on the object to raise it at that height is given by the equation, W = mgh then, the change in the object’s gravitational potential energy is ΔPE = mgh where h = the height above the reference level. If the object is raised from the ground, the reference level is the ground. If the object, however, is raised from the table, the table is the reference level. (Note: The teacher may the previous activity on power to gravitational potential energy)

Direction: Read the questions below and choose the letter of the correct answer. 1. A roller coaster climbing the first hill is an example of A. building kinetic energy. *B. building potential energy. C. gravitational forces. D. nuclear energy.

I.

2.

Of the following units, the one that is a unit of potential energy is? A. Newton *B. Joule C. Meter D. Liter

3.

A stationary object may have *A. potential energy B. velocity C. kinetic energy D. acceleration

Evaluating Learning

4 . A 50 kilogram object is located 5 meters above the ground level. Find its potential energy. *A. The object's potential energy is 2450 J. B. The object's potential energy is 24.50 J. C. The object's potential energy is 2.450 J. D. The object's potential energy is 245.0 J.

J. Additional activities for application or remediation V. REMARKS VI. REFLECTION A.


B.


C.


D.


E.


F.


G.


5. A 12 kg cat who is resting on a tree has a potential energy of 50 Calculate its position (height) relative to the ground. A. The cat is located 0.43 m above the ground. *B. The cat is located 0.43 m above the ground. C. The cat is located 0.43 m above the ground. D. The cat is located 0.43 m above the ground. Journal entry: Write a short paragraph on how potential and kinetic energy is related to your life.


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.



The learners demonstrate an understanding of the propagation of sound through solid, liquid and gas. S8FE –Ie-24  Infer how the movement of particles of an object affect the speed of sound through it. Objective: Infer that sound consists of vibrations that travel through the air. Module III: SOUND Lesson 14: PROPAGATION OF SOUND

II. CONTENT


B.

References 1.


pp. 49 - 51

2.


pp. 71 – 73

3.

Textbook Pages

4.



Lesson Guide G8 First Quarter pp. 52 - 54

IV. PROCEDURES A.


Differentiate kinetic from potential energy. Guessing game: Let the students guess the answer to the question, “ What is a vibration produced by a vibrating body”. They may decode the term by dialing the numbers 76863, in the keypad below. C

B.

Establishing a purpose for the Lesson GHI 4 PQRS 7

ABC 2 JKL 5 TUV 8 0

DEF 3 MNO 6 WXYZ 9

C.


Why do sound vibrates? How does it travel through space?

D.


Do the activity on Sound, Lesson Guide G-8 First Quarter pp. 52-53


Q1. What is the purpose of tapping the tuning fork to a wood or rubber sole? Q2. What causes sound? Q3. What happens to the loudness as you move the tuning fork from up and down? Q4. Can sound be transmitted if there is no matter to form a medium? Q5. How is sound created and transmitted? Q6. What property of a sound wave determines the pitch of a sound?


Discuss the answers in the activity given.

E.

F.

G.


H.


I.

Evaluating Learning

J.



C.


D.


E.


F.


G.

How do you know that there is an approaching train? If you are living near a railway, how does it affect your emotion?

Sound waves are produced by vibrating objects. They are propagated through a medium from the source. Sound waves are longitudinal waves. Particles of the medium vibrate in the direction of wave motion. Write TRUE if the statement is correct and FALSE if the statement is wrong. 1. Sound is a mechanical waves propagating in space. 2. Sound does not need a medium to propagate. 3. Sound wave is a longitudinal wave. 4. Particles of the medium vibrate in the direction of wave motion. 5. Sound carries energy. Bring the following materials by group for the next activity: 1 dowel or 1 wooden rod 1 blue bead 4 colored beads 3 inches of tape 2 large books scissors 5 pieces of string paper slinky spring transistor radio



School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.



The learners demonstrate an understanding of the propagation of sound through solid, liquid and gas. S8FE –Ie-24  Infer how the movement of particles of an object affect the speed of sound through it. Objective: At the end of the activity, learners will be able to infer that sound is transmitted in air through vibrations of air particles Module III: SOUND

Lesson 15: PROPAGATION OF SOUND


B.

References 1.


pp. 49 - 51

2.


pp. 71 – 73

3.

Textbook Pages

4.




IV. PROCEDURES A.


What is sound wave? How is sound produced?

B.


How do you communicate to your love ones miles away from you?

C.


If you flock the string of the guitar one by one how do the sound differs? D.


Do the activity on Transmitting Sound, Lesson Guide G-8 First Quarter pp. 55-56

E.


1. What happens to the other colored beads when the blue bead is tapped? 2. Are there occasion when the beads converge then expand? 3. Are there converging and expanding parts of the slinky? 4. How then is sound classified as a wave?

F.



G.

H.

Finding practical applications of concepts and skills in daily living Making generalizations and abstractions about the lesson

Why are sound important in:  Communication  Signaling system  Music The material through which sound travels is known as the medium. The medium can be a solid, liquid, or a gas. Sound needs a medium to travel. It cannot travel through vacuum. Direction : Choose the letter of the correct answer. 1. Sound is an example of *A. a longitudinal wave. B.. a wave that can travel through a vacuum. C. a transverse wave. D. a wave that does not transmit energy.

I.

Evaluating Learning

2. When sound travel through air, the air particles_______. *A. vibrate along the direction of wave propagation B. vibrate but not in any fixed direction C. vibrate perpendicular to the direction of wave propagation D. do not vibrate 3. Sound is produced due to _____ A. Friction B. circulation *C. vibration D. refraction 4 Sound passes from one place to another in the form of A. Rays *B. waves C. energy D. light 5. Sound waves have A. Amplitude only B. Frequency and wavelength only *C. Amplitude, frequency and wavelength D. Amplitude and wavelength only Define the following characteristics of sound.

J.


• • • • • •

Frequency Amplitude Pitch Loudness Intensity speed

Reference: any PHYSICS book V. REMARKS VI. REFLECTION A. B.

C.

D.

No. of learners who earned 80% in the evaluation No. of learners who require additional activities for remediation who scored below 80% Did the remedial lessons work? No. of learners who have caught up with the lesson No. of learners who continue to require

remediation E.


F.


G.



School

Grade Level

Grade 8


Learning Area

Science

Quarter

First


Content Standards

B.


The learners demonstrate an understanding of the propagation of sound through solid, liquid and gas. S8FE –Ie-24  Infer how the movement of particles of an object affect the speed of sound through it.

C.


II. CONTENT

Objectives: 1.Distinguish the different characteristics of waves; 2. Determine their frequency and wavelength; and 3. Compute the wave speed based on the frequency and wavelength Module III: SOUND Lesson 16: CHARACTERISTICS OF SOUND


B.

References 1.


pp. 51 - 52

2.


pp. 75 – 77

3.

Textbook Pages

4.




IV. PROCEDURES A.


Differentiate the propagation of sound in solid, liquid and in gas

B.


Students will be asked to produce sound by:  whispering,  singing, and  shouting.

C.


Ask them how sound differ in the three situation.

D.

Do the activity on , Lesson Guide G-8 First Quarter pp. 58-59 or



E.

F.


G.


H. Making generalizations and abstractions about the lesson

LM pp75 -77

1. When there are more waves passing through the reference point in a period of time, which wave characteristic also increases? 2. When there are more waves passing through the reference point in a period of time, what happens to the wavelength of the waves? Discuss the answers in the activity given. Discuss the importance of Doppler effect in daily occurrences.  Sound differ from one another in loudness, intensity, pitch and quality. Sound waves have frequency, wavelength and speed.  Loudness depends on the amplitude of vibration.  Intensity depends on the amplitude of vibration and the area of vibrating body perpendicular to the direction of wave motion.  Pitch depends on the frequency of vibration. Pitch is the frequency of a sound as perceived by human ear. A high frequency gives rise to a high pitch note and a low frequency produces a low pitch note. Figure 2 shows the frequencies of same common sounds. The pitch of sound goes up and down.  Sound quality distinguishes one sound from another. Word search: Find word or words that are related to sound

I.

Evaluating Learning

A

A

P

I

T

C

H

L

L

M

I

X

X

D

G

H

J

I

L

S

X

X

S

S

S

D

F

G

H

D

D

D

D

Q

I

N

T

E

N

S

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T

Y

Q

W

E

W

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R

O

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K

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R

1. Differentiate the speed of sound in three medium J.



C.


D.


E.


F.


G.


a. solid b. liquid c. gas see also the list of materials for the next activity (LM pp. 78)


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (PHYSICS)


Content Standards

B.



II. CONTENT

The learners demonstrate an understanding of the propagation of sound through solid, liquid and gas. S8FE –Ie-24  Infer how the movement of particles of an object affect the speed of sound through it. Objective: At the end of the activity, you will be able to distinguish which material transmits sound the best. Module III: SOUND Lesson 17: SPEED OF SOUND


B.

References 1.


pp. 52 - 53

2.


pp. 78 – 80

3.

Textbook Pages

4.




IV. PROCEDURES A.


B.


C.


Differentiate the different characteristics of sound. Place your ear against one end of a tabletop. Ask a friend to gently tap the other end of the table with a pencil or a ruler. What happens? Then ask your friend to gently tap the other end of the table but this time make sure that your ear is above the other end of the table. What happens? On which situation did you encounter louder and more pronounced sound? On which situation did you encounter the sound earlier?

D.


Do the activity on Sound Race.. Where does Sound Travel Fastest?, Lesson Guide G-8 First Quarter pp. 62 - 63 or LM pp. 78 -79 1. Did you hear the watch tick when you held it at arm's length? When you held it against the wooden dowel? When you held it against the metal rod? 2. Did you hear the mobile phone vibrate when you held it at arm's length? When you held it against the wooden dowel? When you held it against the metal rod? 3. Based on your observations, which is a better carrier of sound? Air or wood? Air or water? Air or metal? Water or metal?

E. 4. How did the sound of the spoon change when the string was held against your ears? Discussing new concepts and practicing new skills #2

5. When the ringing of the spoon was too quiet to be heard through the air, could it be heard through the string? 6. Is the string a better carrier of sound than air? 7. Through which material does sound travel fastest? 8. Through which material did sound travel the slowest?

9. Why does sound travel fastest in solids and slowest in air? 10. Do you have any idea what makes sound move fast in solids?

F. G.

Developing mastery (Leads to Formative Assessment 3) Finding practical applications of concepts and skills in daily living

( Note: If there is still time teacher may present a video clip on the transmission of sound www.youtube.com/watch?v=GkNJvZINSEY) If you will make an improvised toy telephone to be given to your baby brother or sister, what are the best materials for the toy telephone to have a very clear voice transmission Why does sound travel faster in solids than in liquids, and faster in liquids than in gases (air)? Sound is nothing more than a local disturbance whose propagation is facilitated by the collisions between particles; this disturbance propagates in a longitudinal wave; imagine one molecule hitting the next molecule, and then that molecule hitting the next, and so forth.

H.


The distances between molecules in solids are very small, i.e., solids are denser - as compared to liquids and gases. Because they are so close, than can collide very quickly, i.e. it takes less time for a molecule of the solid to 'bump' into its neighbor. Solids are packed together tighter than liquids and gases, hence sound travels fastest in solids. The distances in liquids are shorter than in gases, but longer than in solids. Liquids are more dense than gases, but less dense than solids, so sound travels 2nd fast in liquids. Gases are the slowest because they are the least dense: the molecules in gases are very far apart, compared with solids and liquids. Direction: Read the following and write the best letter of your choice.

I.

Evaluating Learning

1. Sound waves travel faster in water than in air because water has a greater ___________. A. density. * B. elasticity. C. number of molecules. D. volume. 2. When a wave travels through a medium_____. A. particles are transferred from one place to another B. energy is transferred in a periodic manner *C. energy is transferred at a constant speed D. none of the above statements is applicable 3. When sound travels through air, the air particles ______.

*A. vibrate along the direction of wave propagation B. vibrate perpendicular to the direction of wave propagation C. vibrate perpendicular to the direction of wave propagation D. do not vibrate 4. Sound waves do not travel through A. solid B. liquid C. gases D. vacuum 5. The method of detecting the presence, position and direction of motion of distant objects by reflecting a beam of sound waves is known as _____. A. RADAR C. MIR

J.


V. REMARKS

A. B.

C.


D.


E.


F.


G.


* B. SONAR D. CRO

Prepare a table indicating the different temperature of the medium (solid, liquid and gas) and the speed of sound.


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.



II. CONTENT

The learners demonstrate an understanding of the propagation of sound through solid, liquid and gas. S8FE-Ie-25  Investigate the effect of temperature to speed of sound through fair testing Objective: Determine how temperature affects the speed of sound. Module III: SOUND Lesson 17: EFFECT OF TEMPERATURE TO THE SPEED OF SOUND


B.

References 1.


pp. 53

2.


pp. 82 - 85

3.

Textbook Pages

4.




IV. PROCEDURES A.


Why does sound travel faster in solids than in liquids, and faster in liquids than in gases (air)?

B.


Picture Analysis:

Figure 1 shows how sound waves varies during the day and during the night

C.

D.



Look closely the picture, any similarities and differences that you can give about the picture? Let the students point out their answers. (answers may vary) How about the arrow on the picture, what does it tell about sound? Now, let us find what happens to the speed of sound when the temperature changes? Be ready for our activity.

Do the activity on Faster sound… In hotter or cooler? Lesson Guide G-8 First Quarter pp. 67 or LM pp. 83- 84

E.


1. Which cylinder gave the loudest sound? 2. Which cylinder gave the highest pitched sound? 3. If pitch is directly dependent on frequency, then, which cylinder gives the highest frequency sound? 4. Since wave speed is directly dependent on frequency, then, which cylinder gives the fastest sound? 5. How would you relate the temperature of the medium with the speed of sound?

F.



G.


Why do we hear loud sound of music on a hot day than on rainy day?


Temperature is a condition that affects the speed of sound. Heat, like sound, is a form of kinetic energy. Molecules at higher temperatures have more energy, thus they can vibrate faster. Since the molecules vibrate faster, sound waves can travel more quickly. The speed of sound in room temperature air is 346 meters per second. This is faster than 331 meters per second, which is the speed of sound in air at freezing temperatures. For every degree rise in temperature, the increase in the speed of sound is 0.6m/s. At 00C, the speed of sound in air is 331m/s. At 10C, the speed will become 331.6m/s. This is determined by the use of the equation: v = 331m/s + (0.6m/s0C) T where

v is the speed of sound T is the temperature of the air.

At a temperature of 10C V = 331m/s + (0.6m/s0C) (10C) V = 331.6 m/s. Speed of Sound H.

358.0 m/s

343.6 m/s

330.4 m/s

Figure 2 shows how speed of sound varies with temperature

From the above figure, notice that the speed of sound varies directly with the temperature-as the temperature increases, the speed of sound also increases. One thing to keep in mind is that this formula finds the average speed of sound for any given temperature. The speed of sound is also affected by other factors such as humidity and air pressure. Direction: Choose the letter of the correct answer. 1. How would you relate the temperature of the medium with the speed of sound? A. The higher the temperature, the faster the sound travels. B. The higher the temperature, the slower the sounds travel. C. The lower the temperature, the faster the sound travels. D. The lower the temperature, the slower the sound travels. 2. What is the speed of the sound in air of 250 C temperature? A. 336m/s B. 325m/s C. 346m/s D. 355m/s I.

Evaluating Learning

3. Calculate the speed of sound if the temperature of the vibrating water is 28°C? A. 346m/s B. 347.8m/s C. 350m/s D. 349.1m/s 4. In which of the following will the movement of particles be the fastest? A. 30°C of water B. 50°C of water C. 70°C of water D. 90°C of water 5. Which of the following quantities tells how hot or cold an object is with respect to some standard? A. Density B. Mass C. Pressure D. Temperature

J.



C.

D.

No. of learners who earned 80% in the evaluation No. of learners who require additional activities for remediation who scored below 80% Did the remedial lessons work? No. of learners who have caught up with the lesson No. of learners who continue to require

What are the properties of sound?

remediation E.


F.


G.



School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.



II. CONTENT

The learners demonstrate an understanding of the propagation of sound through solid, liquid and gas. S8FE-Ie-25  Investigate the effect of temperature to speed of sound through fair testing Objective: Observe how sound waves reflect and refract. Module III: SOUND Lesson 19: PROPERTIES OF SOUND


B.

References 1.


pp. 53 - 54

2.


pp. 85 - 89

3.

Textbook Pages

4.




IV. PROCEDURES A.

B.

C.

D.


How does the temperature affect the speed of sound?


Why do lots of people love to sing inside the bathroom? (possible answers: because of privacy; hard wall surfaces of the bathroom bring about multiple reflection of sound that create pleasing sound; echoes are produce)



Why do you think open field concerts are usually held during nighttime? (possible answer: Sound is heard well in far areas during nighttime that daytime). Do the activity on Properties of Sound, Lesson Guide G-8 First Quarter pp. 74- 76 Station 1: Reflection of Sound Waves Questions: 1. Compare the clearness of sound without the book and with the book as barrier. 2. What happens to the sound waves as it hits the book? 3. Draw the path of sound waves

E.

4. Give example of a reflected sound. 5. How is echo differentiated from reverberation? Discussing new concepts and practicing new skills #2

Station 2: Refraction of Sound Waves Questions: 1. What happens to the loudness of the sound produced by the radio if it is in front of the electric fan? Explain your answer.

2. If the radio is against the electric fan, what happens to the loudness of the sound? Why? 3. Sketch the direction of sound waves in the two given situations. 4. What property of sound is involved? F.




Use the concept of reflection and refraction to explain the pictures G.

Waves have some common properties. The study of the properties of sound waves is called acoustics. Sound waves are reflected when they hit a barrier. Reflection of sound waves off of surfaces is also affected by the shape of the surface. A flat or plane surfaces reflect sound waves in such a way that the angle at which the wave approaches the surface equals the angle at which the wave leaves the surface. Reflection of sound waves off of surfaces can lead to one of two phenomena - an echo or a reverberation. Multiple reflections are called reverberation. A reverberation often occurs in a small room with height, width and length dimensions of approximately 17 meters or less. This best fits the bathroom which enhances the voice.

H.


Refraction of sound on the other hand is describe as the change in speed of sound when it encounters a medium of different density. Sound travels faster in hotter media. This change in speed of sound during refraction is also manifested as sort of “bending” of sound waves.

Figure 2 Refraction of sound waves

Direction: Choose the best answer among the 4 choices.

I.

Evaluating Learning

1. An echo occurs when sound A. is transmitted through a surface. B. is reflected from a distant surface. C. changes speed when it strikes a distant surface. D. all of the above 2. The change in direction of a sound wave around corners is called A. diffraction B. interference

C. refraction

D, interference

3. You can hear noises a long distance away over water at night because A. of lowered temperature. B. water conducts sound better at night. C. sound is reflected off water more efficiently at night. D. of refraction of sound in air. 4. The method of detecting the presence, position and direction of motion of distant objects by reflecting a beam of sound waves is known as _____. A. RADAR B. SONAR C. MIR D. CRO 5. The technique used by bats to find their way or to locate food is _______. A. SONAR B. RADAR C. ECHOLOCATION D. FLAPPING J.


What is light?

V. REMARKS VI. REFLECTION

A. B.

C.


D.


E.


F.


G.



DAY: I. OBJECTIVES

School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)

A.

Content Standards

B.


C.


II. CONTENT

The learner demonstrates understanding of some properties and characteristics of visible light. The learner shall be able to discuss phenomena such as blue sky, rainbow and red sunset using the concept of wavelength and frequency of visible light (S8FE-If-26)  Demonstrate the existence of the color components of visible light using a prism or diffraction grating Objectives: 1. Describe refraction. 2. Use refraction to explain apparent changes of the positions of things we see. 3. Describe the behavior of light as it travels from one medium to another. Module IV: LIGHT Lesson 20: REFRACTION OF LIGHT RAYS


B.

References 1.


55-56

2.


94-97

3.

Textbook Pages

4.


Other Learning Resource IV. PROCEDURES

A.

B.

C.

D.





How do sound waves reflect and refract? Light exhibits the characteristics and properties of a wave. Light tends to travel in a straight line, unless it is acted on by some external force or condition. "What kinds of forces or conditions can affect light, and how?" To answer this question, we start with what we can see in everyday life. from each other.

Why do our finger look swollen or big when we dip it into the water? Ask the students if they know the meaning of work. Emphasize to them that the meaning /definition of work and the one that we use in Science are quite different.

Activity-See Lesson Guide pp 77-78 Analysis:

E.

Part A: 1. List and arrange the observed colors according to how they appear on the paper. Part B. 2. Describe the position of the different colors after passing through the prism Discussing new concepts and practicing new skills #2

3. Explain the dispersion of white light. Why is the prism or water able to separate the colors of white light? 4. Compare your results in the first part with your results in the second part. Are there any differences? What might account for the differences? 5. What did you observe with the indices of refraction of the colors of light in the acrylic prism?

6. How would this indices of refraction account for the arrangement of colors of light? F. Developing mastery (Leads to Formative Assessment 3)


G

Finding practical applications of concepts and skills in daily living When driving on a black road on a hot day, you may see what appear to be a puddle of water up ahead of you. But when you get there, it is dry. Why? What is this phenomenon called? (a mirage) Light travels in a straight line. This is so as long as long as the medium in which it is traveling is uniform all throughout. When light crosses a boundary between two transparent media of different optical densities, light bends. The bending of light due to change in its speed is called refraction. When light travels from air to water, the speed of light decreases because the optical density of water is greater than air.

H.


Light travels in a straight line. This is so as long as long as the medium in which it is traveling is uniform all throughout. When light crosses a boundary between two transparent media of different optical densities, light bends. The bending of light due to change in its speed is called refraction. When light travels from air to water, the speed of light decreases because the optical density of water is greater than air. In figure 3, θi is the angle of incidence and θr is the angle of refraction (the angle between the outgoing ray, in the medium, and the normal to the boundary). As light enters an optically more dense material, the angle of refraction is smaller than the angle of incidence-the light bends toward the normal. Likewise, if light passes from an optically dense medium to a less dense medium, the light bends away from the normal. A known indicator of the optical density of a material is the index of refraction of the material. Index of refraction represented by the symbol n is the ratio of the speed of light in vacuum and its speed in another medium. In symbols; n= speed of light in a vacuum speed of light in material The ratio is always greater than 1. For water, n is usually equal to 1.360 while air is more or less comparable to vacuum so its n is 1.000. In figure 3, θi is the angle of incidence and θr is the able of refraction (the angle between the outgoing ray, in the medium, and the normal to the boundary).

As light enters an optically more dense material, the angle of refraction is smaller than the angle of incidence-the light bends toward the normal. Likewise, if light passes from an optically dense medium to a less dense medium, the light bends away from the normal. A known indicator of the optical density of a material is the index of refraction of the material. Index of refraction represented by the symbol n is the ratio of the speed of light in vacuum and its speed in another medium. In symbols; n= speed of light in a vacuum speed of light in material The ratio is always greater than 1. For water, n is usually equal to 1.360 while air is more or less comparable to vacuum so its n is 1.000.

Direction: Complete each statement by supplying the correct term. You may choose the answer from the box below.

Refraction Mirage

bends towards the normal incident ray

bends away from the normal

I.

Evaluating Learning

medium

1. The bending of light when it passes obliquely from one medium to another is known as ________. (refraction) 2. Refraction is the bending of light from one ________ to another. (medium) 3. When light passes from a less dense to a denser medium, it _____. (bends towards the normal) 4. When a light ray passes from water to air (denser to a less dense medium), its path __________. (bends away from the normal) 5. The phenomenon that motorists observe on hot days when the road seems to be covered with water. (mirage)

J.




B.


C.


D.


E.


F.


G.

What innovation or localized materials did I

What are the different colors of light?

Use or discover which I wish to share with other teachers?


DAY:

School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)

I. OBJECTIVES

A.

Content Standards

B.


C.


The learner demonstrates understanding of some properties and characteristics of visible light. The learner shall be able to discuss phenomena such as blue sky, rainbow and red sunset using the concept of wavelength and frequency of visible light (S8FE-If-26)  Demonstrate the existence of the color components of visible light using a prism or diffraction grating. Objectives: Infer that: (a) white light is made up of many different colors of light and (b) each of these colors of light bends differently when it strikes objects like a prism. Module IV: LIGHT Lesson 21: DISPERSION


B.

References 1.


2.


3.

Textbook Pages

4.


57-60 98-100


A.


B.


Describe the behavior of light as it passes from one medium to another

What do you see in the picture? Are you fond of rainbow hunting?

C.

D.



Have you ever wondered how rainbow appears in a clear sky? How rainbow form and what are the colors of the rainbow?

Activity-see Lesson Guide pp. 82-83 Analysis:


Part A: 1. List and arrange the observed colors according to how they appear on the paper.

Part B. 2. Describe the position of the different colors after passing through the prism. 3. Explain the dispersion of white light. Why is the prism or water able to separate the colors of white light?

E.

4. Compare your results in the first part with your results in the Second part. Are there any differences? What might account for the differences? 5. What did you observe with the indices of refraction of the colors of light in the acrylic prism? 6. How would this indices of refraction account for the arrangement of colors of light?

F.


Discuss the answer in the activity given

Do you agree in the saying that “At the end of a rainbow is a pot of gold”. Why or why not.

G.


Upon passage through the prism, the white light is separated into its component colors - red, orange, yellow, green, blue and violet. The separation of visible light into its different colors is known as dispersion. Dispersion is a special kind of refraction which provided us colors of light. It occurs whenever there is a process that changes the direction of light in a manner that depends on wavelength. Dispersion can occur for any type of wave and always involves wavelength-dependent processes. For a given medium, n increases as wavelength decreases and is greatest for violet light. Thus violet light is bent more than red light, as can be seen with a prism. Refer to the figure below.

H.


Figure 1. Dispersion of white light into bands of colors In a rainbow, light enters a drop of water and is reflected from the back of the drop. The light is refracted both as it enters and as it leaves the drop. The formation of a rainbow involves a series of physical phenomena - reflection, refraction, dispersion and total internal reflection. The occurrence of each of these is due to the

interaction of light with air and water and the boundaries between them.

Fill in the missing term: 1. The splitting of white light into several colors on passing through a glass prism is due to____. 2. When does a rainbow occur in nature? _____ 3. Rainbow formation is due to_____. 4. Which color is bent the most? ____ 5. Which color is bent the least? ___ I.

Evaluating Learning Answers: 1. Dispersion 2. After the rainstorm, when the sun comes out 3. the properties of light namely reflection, refraction ,total internal reflection and dispersion 4. violet 5. red

Which colors of light receives least energy? Most energy? Explain your answer.



B.


C.


D.


E.


F.


G.



DAY:

School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)

I. OBJECTIVES A.

Content Standards

B.


C.


II. CONTENT

The learner demonstrates understanding of some properties and characteristics of visible light. The learner shall be able to discuss phenomena such as blue sky, rainbow and red sunset using the concept of wavelength and frequency of visible light (S8FE-If-27)  Demonstrate the existence of the color components of visible light using a prism or diffraction grating Objectives: Infer that: 1. energy of the colors of light increases as one goes towards the right side of the color spectrum; 2. red light has the least energy and violet light has the most energy. Module IV: LIGHT Lesson 22: COLORS IN RELATION TO ENERGY


B.

References 1.


61

2.


103-105

3.

Textbook Pages

4.



A.


B.


C.


D.


Describe the position of the different colors after passing through the prism. Why do you think we tend objects as having fixed colors? For example, an apple is red. In reality, an object’s appearance results from the way it reflects the particular light that is falling on it. Under white light, the apple appears red because it tends to reflect light in the red portion of the spectrum and absorb light. Activity see Lesson Guide pp. 85-86 Analysis:

E.

F.


1. Which thermometer registered the lowest temperature? 2. Which thermometer registered the highest temperature? 3. Which colored plastic allowed more energy to pass through it? 4. Which colored plastic allowed the least energy to pass through it? 5. From your answers in 3 and 4, which color of light has the least energy? The most energy?


Discuss the answers in the activity given Explain the following:


1. Why the sky is blue? The sky appears blue because of the scattering of blue and violet light from the sunlight in the atmosphere. Violet light is more scattered than blue light; however, our eyes are most sensitive to blue, thus we see a blue sky.

2. Why the sunset is red? During sunset, the path through which the light travels in the atmosphere becomes longer. As a consequence, more blue and violet are scattered from sunlight. Thus, less blue light reaches the ground and the light that reaches the Earth’s surface is red.

G

3. Why the clouds are white? Clouds are made up of cluster of water droplets of different sizes. Since the color of scattered light depends on the size of the particles, the different-size clusters scatter a variety of colors. The smallest clusters scatter blue light resulting in blue clouds; the medium-sized cluster make green and the larger ones make red. The combination of these result in white cloud Energy is directly proportional to the frequency of the light. The list of colors goes from low frequency to high frequency. Red Orange Yellow Green Blue Indigo Violet. Red has the lowest frequency, so red has the lowest energy. Violet has the highest frequency, so violet has the highest energy.

H.


Our eyes are sensitive to light which lies in a very small region of the electromagnetic spectrum labeled "visible light". This "visible light" corresponds to a wavelength range of 400 - 700 nanometers (nm) and a color range of violet through red. The human eye is not capable of "seeing" radiation with wavelengths outside the visible spectrum. The visible colors from shortest to longest wavelength are: violet, blue, green, yellow, orange, and red. Ultraviolet radiation has a shorter wavelength than the visible violet light. Infrared radiation has a longer wavelength than visible red light. The white light is a mixture of the colors of the visible spectrum. Black is a total absence of light.

Directions: Choose the letter of the correct answer. 1. Which of the following lights has the highest frequency? a. red b. blue c. green d. violet 2. What do different wavelengths of light represent? speed b. amplitude colors d. frequency

I.

Evaluating Learning

3. A rainbow usually appears in the sky after a rain. Which of the following statements best explain this observation? a. Raindrops acts as prism separating sunlight into colors. b. The white clouds actually prism composed of different colors. c. The colors of the rainbow comes from the raindrops in the atmosphere d. When sunlight is reflected by the ground towards the clouds, it separate into different colors. 4. Which of the following has the longest wavelength? a. red b. violet c. orange d. green 5. The process of separating white light into bands of colors using a prism is known as _________. a. refraction b. dispersion c. reflection d. diffraction

J.


Prepare a color wheel. Please refer to LM pp. 103 – 105 for the materials and procedure.



B.


C.


D.


E.


F.


G.



School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Science)

DAY: I. OBJECTIVES

A.

Content Standards

B.


C.

The learner demonstrates understanding of some properties and characteristics of visible light. The learner shall be able to discuss phenomena such as blue sky, rainbow and red sunset using the concept of wavelength and frequency of visible light S8FE-If-28  Explain that red is the least bent and violet the most bent according to their wavelengths or frequencies. Objectives:


II. CONTENT

Infer that: 1. light is composed of colors of different frequencies and wavelength; 2. the frequencies of the colors of light are inversely proportional to the wavelength; 3. the arrangement of colors of light shows the hierarchy of the color’s corresponding energy. Module IV: LIGHT Lesson 23: REFRACTIVE INDEX OF THE COLOR OF LIGHT


B.

References 1.


2.


3.

Textbook Pages

4.


61 105-110


A.


Which colors of light has the least energy? Most energy? Study and analyze the pictures of the stars at night.

B.


C.


Do you think they have the same energy? Explain your answer.

D.


Activity-see Lesson Guide pp. 90-91 Analysis:


1. Which color registered the highest frequency? shortest wavelength? 2. Which color registered the lowest frequency? longest wavelength? 3. What did you observe about the wavelengths and frequencies of the different colors of light?

E.

4. What did you observe about the products of frequencies and wavelengths? 5. Does the frequencies of the colors of light increase from red to violet? 6. What did you observe about the corresponding energies from red to violet? 7. How is frequency relate to energy of colors of light?

F.



The effects of colored light on people have been studied by psychologists. They found out that people do show varied responses to different colors. Colors influence a person’s emotion and degree of activity.

G. Finding practical applications of concepts and skills in daily living

According to psychologists: 1. Red light/color may bring about a rise in blood pressure, respiration rate, and frequency of blinking. It excites people. 2. Blue light/color produces effects opposite to those red light; hence, it lessens activity. 3. Purple has a mournful effect. 4. Yellow is joyful and green has a peaceful effect. Knowing all these, would you: a. choose red paint/wall paper for your bedroom? b. wear black during summer? c. wear light colored shirt during cold days What is the relationship between wavelength, frequency and energy? The greater the energy, the larger the frequency and the shorter (smaller) the wavelength. Given the relationship between wavelength and frequency — the higher the frequency, the shorter the wavelength — it follows that short wavelengths are more energetic than long wavelengths.

H. Making generalizations and abstractions about the lesson

How are temperature and color related? The amount of light produced at each wavelength depends on the temperature of the object producing the light. Stars hotter than the Sun (over 6,000 degrees C) put out most of their light in the blue and ultraviolet regions of the spectrum. Stars cooler than the Sun (below 5,000 degrees C) put out most of their light in the red and infrared regions of the spectrum. Solid objects heated to 1,000 degrees C appear red but are putting out far more (invisible) infrared light than red light. How are wavelength and temperature related? All objects emit electromagnetic radiation, and the amount of radiation emitted at each wavelength depends on the temperature of the object. Hot objects emit more of their light at short wavelengths, and cold objects emit more of their light at long wavelengths. The temperature of an object is related to the wavelength at which the object gives out the most light.

The assessment for the day will be based on the outcome/output of the activity: the color wheel. It will be graded based of the rubric below.

I.

Student was mindful of classroom rules/procedure Student follows direction Student labeled the output correctly(colors and fractional parts Colors placed in appropriate place on color wheel The finish product was neat. TOTAL POINTS:

Evaluating Learning

J.


Give the meaning of heat and temperature



B.


C.


D.


E.


F.


G.



School

Grade Level

Grade 8

Teacher

Learning Area

Physics

Teaching Date and Time

Quarter

First


Content Standards

B.


The learner demonstrates understanding of heat and temperature, and the effects of heat on the body. (S8FE-Ig--29)

C.

Differentiate heat and temperature at the molecular level.


Objectives: 1. Distinguish between temperature and heat. 2. Describe the hotness or coldness of an object in terms of its temperature 3. Compare the changes in the temperature of water to determine the relationship between the amount of heat transferred and the resulting temperature change. Module V: HEAT Lesson 24: HEAT TRANSFER


B.

References 1.


2.


3.

Textbook Pages

4.


28-29 38-40


A.

B. C. D.

Reviewing previous lesson or presenting the new lesson Establishing a purpose for the Lesson

What are the three methods of transferring energy? (conduction, convection and radiation) Ask students to jog in place for 15 seconds.


What do you feel after performing the jogging activity?


Activity- See Leeson Guide pp. 94-95 1. What actually transferred when you dipped your finger into the water? In what direction did it transfer? 2. Was the water ‘hot’ or ‘cold’? Explain. 3. How close is your estimated value to the measured temperature of the water?


4. Which container feels ‘hottest’? Which container feels ‘coolest’? 5. What do you think causes the difference in the hotness or coldness of the water inside the containers? 6. In which container(s) is heat transfer taking place? What evidence best supports your answer? Within this container, which absorbs heat? Which gives off heat? 7.In which container was there the greatest amount of heat transfer? What is the basis of your answer?

8. How are the amount of heat transferred and the change in temperature of water related? F.

G.




In a bakery, when do cookies cook faster, is it at lower temperature or at higher temperature? Explain your answer.

Watch video clips about heat and temperature www.youtube.com/watch?v=wTi3Hn09OBs

H.


Heat is the total energy of molecular motion in a substance while temperature is a measure of the average energy of molecular motion in a substance. If heat is absorbed or given off by an object, its temperature changes. If the object absorbs heat its temperature rises while if the object gives off heat its temperature decreases. Heat is transfer of (thermal) energy between objects or places due to temperature differences. Heat transfers from an object of higher temperature to an object of lower temperature.

Direction: Read each question carefully. Choose the letter of the correct answer. 1. Which of the following energies is transferred from one thin to another because of the temperature differences between things? A. Heat B. temperature C. Kinetic energy D. internal energy 2. The natural flow of heat is always from ________. A. hot to cold C. cold to hot B. lower temperature to higher temperature D. both A and 3. What causes an ice to melt? A. the change in weather B. the presence of hot water C. the absorption of the heat from its surrounding D. the release of heat to the cooler surrounding 4. Which of the following will likely happen when a hot and a cold are put in contact with one another? A. The hot and the cold object will become colder. B. The hot and the cold object will become hotter. C. The cold object will become colder while the hot object will become hotter. D. The cold object will become warmer while the hot object will become colder.

I. Evaluating Learning

5.How are the amount of heat transferred and the change in temperature of water related? A. The change in temperature is inversely proportional to the heat transferred. B. The amount of heat transferred is proportional to the change in temperature. C. The amount of heat transferred is inversely proportional to the temperature. D. There is no relation between the heat transferred and the change in temperature. Answe J.




B. No. of learners who require additional activities for remediation who scored below 80% C.


D.


E.


F.


G.


How is temperature related to the kinetic energy of particles?


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.


The learner demonstrates understanding of heat and temperature, and the effects of heat on the body. (S8FE-Ig--29)

C.


II. CONTENT

Differentiate heat and temperature at the molecular level.

Objectives: 1.Explain the scattering of the dye in water at different temperature. 2.Describe the relation of the temperature of the water to the rate of scattering of the dye. Module V: HEAT Lesson 25: EFFECT OF TEMPERATURE ON PARTICLES OF MATTER


B.

References 1.


29-31

2.


41-43

3.

Textbook Pages

4.



A.

B.

C.

D.





How will you describe the transferring of heat from one body to another? Use the following demonstration to begin a discussion on the effect of temperature on particle movement. Blow up a balloon, and then aim a hair dryer on low setting at the balloon, and watch it rise. Questions: 1 .What happens when I blow hot air on the balloon? Why? 2. What is happening to the air inside the balloon? 3. What do you think would happen if the balloon was placed in a cold car? 4. What would happen to the balloon as the temperature increases in the car? Why? 5. Ask the students to think about what might happen to a balloon in a bottle when it is heated. Activity- see Lesson Guide pp 99-101 1. What similarities and differences did you observe when a drop of dye was added to each container?

E.


2. In which container did the dye scatter the fastest? In which did it scatter the slowest? 3. How do you relate the temperature of the water to the rate of scattering of the dye?

4. In which container are the particles of water moving fastest? In which container are the particles moving slowest? 5. How is temperature related to the speed of the particles? 6. How is temperature related to the kinetic energy of particles?

F.

G.

H.





Watch the short video clip on Relation Between Temperature and Molecular Movements, you my download the video on www.youtube.com/watch?v=ZqVC10Q1jcQ, then answer the question that follows? During hot day why do we prefer drinking cold water than hot water? If heat is added to an object, the particles of the object gain kinetic energy and they move faster. Since temperature is directly related to kinetic energy, any gain in kinetic energy would cause the temperature to increase. Conversely, if heat is transferred or removed from an object, it loses kinetic energy, its particles move slower and the body’s temperature decreases.

Direction: Read each question carefully. Choose the letter of the correct answer. 1. When the temperature of an object increases, the average kinetic energy of the molecules ________. A. increases B. decreases C. remains the same D. becomes colder 2. In which of the following will the movement of particles be the fastest? A.30 0C of water C. 70 0C of water B.50 0C of water D. 90 0C of water 3. The _________ in/the temperature of the water, the greater the speed of the moving particles. A. lower B. higher C. decrease D. changes

I.

Evaluating Learning

4.The quantity that tells how hot or cold an object is with respect to some standard A. mass B. heat C. pressure D. temperature 5.Which of the following should be done when measuring the temperature of water in a glass container? A. Stir the water using the thermometer to get the temperature faster. B .Avoid letting the thermometer get in contact with any side of the container. C. Shake the thermometer vigorously before getting the temperature of the water. D. Let the tip of the thermometer touch the glass container to get the temperature faster. Answer Key : 1. 2. 3. 4. 5.

A D B D B



B.


C.


D.


E.


F.


G.


How do temperature affects thermal expansion of some objects?


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.


The learner demonstrates understanding of heat and temperature and the effects of heat on the body.

(S8FE-Ig-29)  Differentiate between heat and temperature at the molecular level.


II. CONTENT

Objectives: 1. Define thermal expansion 2 .Determine experimentally how temperature affects thermal expansion of some objects. Module V: HEAT Lesson 26: THERMAL EXPANSION


B.

References 1.


31

2.


43-44

3.

Textbook Pages

4.



A.


B.


C.


D.



G

You are very familiar to a device called thermometer. You have most probably used this device many times. The one commonly available in our school laboratory is the liquid thermometer.

Why does the liquid inside the tube of the thermometer go up and down? Does the working principle of the mercury/alcohol thermometer also true to most solids?

Activity-see Lesson Guide pp 103-104 Analysis:

E.

F.

How is temperature related to the kinetic energy of particles?



1. What happens to the height of the weight when the wire is heated? 2. What factors affect the expansion of the wire? 3. Identify the effects of thermal expansion and contraction to some materials. Discuss the answers in the activity given There are some applications of thermal expansion in day-to-day life. Some of them are the following, or you may watch this short video www.youtube.com/watch?v=4UE_cxd7TEw for some practical application of thermal expansion used at home.

Possible answers: What are the Engineering Applications of Thermal expansions? 1. Railway track: Railway tracks are an example where the concept of thermal expansion is used. Space is left between railway tracks as an allowance for their expansion when temperature increases, otherwise the rails may buckle. 2. Steel Bridges: Similarly, long steel bridges are designed to include expansion joints to allow for their expansion, by fixing one end and resting other end on rollers. 3. Mercury Thermometers: Thermal expansion is applied in mercury that contains liquid, the volume of which changes as the temperature varies. Liquid occupy less space when cold, but additional space is needed when temperature varies. As the liquid expands, its volume changes and it is forced to flow along the tube that is calibrated to show the temperature. (Note: Mercury thermometer is now being banned to be used in science laboratory because of its health hazards.) 4. Bi-metal strip Thermometers: Bi-metal strips in a mechanical thermometer possess co-efficient of thermal expansion, due to which their expansion with a rise in temperature is different. The strips sin bend since the expansion or contraction of the material used is not similar. This concept is used in measurement of temperature. 5. Automobile Engine Coolant: The concept of thermal expansion is also used in systems of engine coolant in automobiles. If coolant is filled in the radiator with engine in a cold condition, it will spill over with the heating of engine during operation. Thus an overflow tank is fitted that accumulates such coolant during thermal expansion, and as engine is cooled, it returns to the radiator. Thermal expansion is another effect of heat transfer. It does not apply only to the liquid inside the thermometer. In fact, it applies to almost everything around us, be it a solid, a liquid, or a gas.

H.


What is thermal expansion and how does it work? Thermal expansion is the tendency of matter to change in volume in response to a change in temperature, through heat transfer. Temperature is a monotonic function of the average molecular kinetic energy of a substance. When a substance is heated, the kinetic energy of its molecules increases. What must happen to the temperature of a material for thermal expansion to occur? Factors affecting thermal expansion. Imagine that a long, thin metal wire is heated. The wire expands. The amount by which it expands depends on three factors: its original length, the temperature change, and the thermal (heat) properties of the metal itself.

Direction: Read each question carefully. Then select the letter of the correct answer. 1. A person cannot unscrew the lid of a pot of jam. He finds that the lid can be unscrewed after it has been held under hot water for a few seconds. Why he has to do this? A. The air pressure in the jar falls B. The jam melts C. The lid expands D. The glass expands. 2. The change in length of an object when it undergoes a temperature change is related to A. its mass B. its original length. C. the magnitude of the temperature change. D. both B and C I.

Evaluating Learning

3. The change in length of an object subjected to a change in temperature directly depends on A. its material of which it is made. B. the change in temperature. C. the original length of the object. D. all of these. 4. The working of a simple thermostat depends on A. thermal expansion. B. specific heats. C. the second law of thermodynamics. D. condensation 5. An axle is too large to fit into the hole in a wheel that is made of the same metal. How can the axle be made to fit into the hole. A. by heating the wheel alone B. by cooling both the axle and the wheel C. by cooling the axle alone D. by heating both the axle and the wheel

J.




B.


C.


D.


E.


F.


G.


What is the effect of temperature change on phase changes?


School

Grade Level


Learning Area Quarter

Grade 8 SCIENCE First (Physics)

DAY: I. OBJECTIVES

A.

Content Standards

B.



C.


(S8FE-Ig-29)  Differentiate between heat and temperature at the molecular level Objective: Explain the effect of temperature change on phase changes.

Module V: HEAT Lesson 27: PHASE CHANGE


B.

References 1.


2.


3.

Textbook Pages

4.


31-33 45-48


A.

B.



What is thermal expansion? How does it work? The students need to understand the difference between particles in a gas, liquid, and a solid. Have students look at the Gases, Liquids, and Solids page on the Purdue University Chemistry Department website (https://www.chem.purdue.edu/gchelp/liquids/character.html) Here they will see how the characteristics of solids, liquids, and gases can be explained by particle motion.

Discuss what happens at both the observable and molecular level in these scenarios: C.

D.


1. Water is placed in the freezer. 2 .Ice melts. 3. A puddle evaporates.


Activity-see Lesson Guide pp. 109


Station 1 : 1. Why does the ice inside the container melt after sometime? 2. Describe the temperature of the water while the ice melting. 3 .Describe the temperature of the water after the ice has melted.

E.

4 .Which is your dependent variable? Which is your independent variable? (Note that the independent quantity is plotted along the X axis while the dependent quantity is plotted along the Y-axis. 5. Describe your graph 6 .What can you say about the one variable as the other variable changes? What relationship can be infer from the graph? Station 2: 1. Describe and interpret your graph. 2. What similarities and differences have you noticed between your graphs obtained from Station 1 and Station 2? F.


Discuss the answer in the activity given What is the importance of phase change in the preparation of home-made ice cream?

G.


H.


Ice is in solid form. Therefore, its particles are actually moving more slowly (still locked in lattice position) than those in the liquid brine (sliding past). Any thermal energy absorbed from the cream will first be used to raise the temperature of the brine (which requires more energy to accomplish because of the solute). Once the average kinetic energy of the molecules (aka: temperature) in the brine has increased enough, then they will begin to transfer energy to the ice, and it will again begin to melt. The temperature of the brine will not increase above the melting point until all of the ice has melted (all energy is used to accomplish phase change before increasing temperature. Changing the amount of heat energy usually causes a temperature change. However, DURING the phase change, the temperature stays the same even though the heat energy changes. This energy is going into changing the phase and not into raising the temperature. That's why water doesn't get hotter while it boils. The temperature remains constant until the phase change is complete. When a substance changes from one state, or phase, of matter to another we say that it has undergone a change of state, or we say that it has undergone a change of phase. For example, ice melts and water; water evaporates and becomes water vapor. These changes of phase always occur with a change of heat. Heat, which is energy, either comes into the material during a change of phase or heat comes out of the material during this change. However, although the heat content of the material changes, the temperature does not. Assessment:

I.

Evaluating Learning

Direction: Read each statement carefully and write the letter of the best answer. 1.When a solid, liquid or a gas changes from one physical state to another, the change is called A. Melting B. Phase change C. Solidification D. Freezing 2.A solid undergoes a phase change to liquid state it A. releases heat while remaining at constant temperature B. absorbs heat while remaining at a constant temperature C. releases heat as the temperature decreases D. absorbs heat as the temperature increases 3.The condensation of water vapor actually A. Warms the surroundings B. Cools the surroundings C. Sometimes warm sometimes cools D. Neither warms nor cools the surroundings 4.The phase change occurs when a solid changes to a liquid. A. Freezing B. Sublimation C. Melting D .Evaporation 5.The phase change occurs when a liquid becomes a solid. A .Freezing B. Sublimation C. Melting D. Evaporation

J.

Additional activities for application or Remediation



B.


C.


D.


E.


F.


G.


What is heat capacity?


School

Grade Level


Learning Area Quarter

Grade 8 SCIENCE First (Physics)

DAY: I. OBJECTIVES

A.

Content Standards

B.




(S8FE-Ig-29)  Differentiate between heat and temperature at the molecular level Objective: Compare the heat capacities of the given liquid samples.

II. CONTENT

Module V: HEAT Lesson 28: HEAT CAPACITY


B.

References 1.


34

2.


49-51

3.

Textbook Pages

4.



A.


B.


C.

D.

Presenting examples / instances of the new lesson Discussing new concepts and practicing new skills #1

Explain the effect of temperature change on phase changes.

Even if the objects are at the same location they have different temperatures. Have you ever been outside in the playground during one sunny day and suddenly touch the metal of a swing set? How does it feel? Is it hot? Yes! How about walking barefoot on a sunny day? Have you ever walked on the sidewalk and had to jump to the grass because the pavement was too hot for your feet? Do you think the grass and the pavement are actually different temperatures? Activity see Lesson Guide pp. 112-113

1. Which liquid requires more time to increase in temperature by 5 degrees? Explain. 2. Which liquid requires more heat to increase in temperature by 5 degrees? Explain. E.

F.



3. Which liquid has a greater heat capacity? Why?


G


Substances that have a high specific heat capacity are suitable as a material for constructing kettle handlers, insulators and oven covers, because, a high amount of heat will cause only a small change in temperature and the material won't get hot too fast! The amount of heat needed by a material to increase its temperature by a degree is called heat capacity (C). To be more specific, the term specific heat capacity (c) is used, and this refers to the amount of heat required to increase the temperature of one unit mass of a given material by one Celsius degree. For example, water has a specific heat capacity of 1 cal/g°C. So it takes 1 calorie of heat to raise the temperature of 1 gram of water by 1°C. It is expressed in the equation:

H.


H = mc ∆T Where: H is the amount of heat, C is the specific heat, and ∆T is the change in temperature Different materials have different specific heat capacities. Many metals have low specific heat capacities. This makes them easy to heat up and cool down. Water, on the other hand, has a high specific heat capacity and so it takes a long time to heat and a long time to cool. This makes the water a good coolant for car radiators. Because of its high specific heat capacity, it can absorb a large amount of heat without causing its temperature to rise too high. Direction: Read the statement carefully and choose the best answer. 1. The amount of heat required to raise the temperature of a body by 10C is called ______? A. Specific heat C. Temperature

B .Heat D. Heat capacity

2. The amount of heat required to raise the temperature of a unit __________of a material by 10C is called its heat capacity. A. Volume B. Mass C. Weight D .Density 3.The specific heat capacity of water is A.1 cal/g°C C.1 cal/g°C

I.

Evaluating Learning

B.1.5 cal/g°C D.1.1 cal/g°C

4. Which of the following statements about heat capacity is correct? A. The energy that is transferred from one object to another B. The difference between internal and external energy C. The amount of energy needed to raise the temperature of a substance by 1 degree Celsius D. The amount of energy that is naturally within an object 5. Why does the temperature of the ocean not fluctuating as much as the temperature of sand? A. Water has higher heat capacity. B. Neither of these answers are correct. C. Both of these answers are correct. D. The mass of the ocean is greater 6 .A substance with higher specific heat will ________. A. warm faster than other substances B. warm slower than other substances C. cool faster than other substances D. warm at the same rate as other substances 7. Why does the temperature of the ocean not fluctuating as much as the temperature of sand? A. Water has higher heat capacity. B. It takes a short time to heat.

C. Water has low specific heat capacity. D. The mass of the ocean is greater. 8. The quantity of heat required to increase the temperature of a unit mass of the substance by 1oC is called ________. A. heat B. internal energy C. temperature D. heat capacity 9. Metals are both good heat conductors and electrical conductors because of the A. similarity between thermal and electrical properties. B. looseness of outer electrons in metal atoms. C. relatively high density of metals. D. high elasticity of metals. 10. Which of the following statements about heat capacity is correct? A. The energy that is transferred from one object to another B. The difference between internal and external energy C. The amount of energy needed to raise the temperature of a substance by 1 degree Celsius D. The amount of energy that is naturally within an object Define the following terms:


J.



B.


C.


D.


E.


F.


G.


1. electricity 2. electric current 3. voltage 4. ammeter 5. voltmeter


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.


C.


II. CONTENT

The learners demonstrate an understanding of current-voltageresistance relationship, electric power, electric energy and home circuitry. The learners shall be able to practice safety in handling electrical devices.  S8FE – Ih-30 Infer the relationship between current and charge Objectives: 1. Measure the electric current and voltage in a circuit using an ammeter and voltmeter respectively; and 2. Determine the relationship between: a. electric current and voltage b. electric current and resistance 3. State Ohm’s Law Module VI: ELECTRICITY: Lesson 29: OHM’S LAW: RELATIONSHIP AMONG CURRENT, VOLTAGE AND RESISTANCE


B.

References 1.


pp. 36 – 38

2.


pp. 55 - 58

3.

Textbook Pages

4.



Lesson Guide in Grade 8 – First Quarter pp. 116 - 120

IV. PROCEDURES A.


How do your daily activities being affected by electricity?

B.


Show to the students the voltmeter and ammeter and ask them if they are familiar with the materials. Teach them how to use and connect properly the ammeter and voltmeter in the circuit.

C.


There are three quantities that you should be familiar with the study of electricity. Let us find out in this activity

D.


Do the activity on Measuring Current and Voltage Lesson Guide G-8 First Quarter pp. 116 -117

E.


No. Voltage Current Voltage/Current of V I V/I dry ( volts) ( volt/ampere cells ampere) 1 2 3 1. Compare the brightness of the bulb with one dry cell to its brightness when there are two dry cells in the circuit, three dry cells in the circuit. 2. What can be inferred about the current passing through the bulb? 3. What can be inferred about the voltage across the bulb?

4. When you graphed the voltage against current, what is the shape of the graph line? What does it mean? 5. Look at column 4. What kind of values did you obtain? What does this indicate?

From the activity, notice that the current increases when the voltage increases for a common resistance. This only proves that current is affected by voltage. Plotting the data of V vs. I gives a straight line graph through the origin as shown in the figure below.

F.


Such graph indicates that voltage is directly proportional to the current that is V α I or V=kI Where k, the proportionality constant, is the slope of the V vs. I graph. Note that: k = V/I This constant k is equal to the resistance R, of the circuit, so R = V/I From the equation, the unit of electrical resistance is defined as

G.


In household wiring we use different kind of wires such as aluminum, nichrome and copper. Why is it that others prepare to use copper for household circuits. (answer: copper cabling has a lower resistance than aluminum for the same length, so copper is safer to use for household circuits) Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship:

H.

Making generalizations and abstractions about the lesson where I is the current through the conductor in units of amperes. The rate of the flow of electricity is the current. The ammeter is the instrument used to measure current. V is the voltage measured across the conductor in units of volts. The instrument that directly measure this is the voltmeter, and R is the resistance to the flow of electrons in the conductor, is expressed in ohms Ω. Using an ohmmeter is one way of directly measuring electrical resistance. Direction: Choose the letter of the correct answer.

I.

Evaluating Learning

1. Which statement regarding Ohm's Law is correct? A. When resistance increases in a circuit with a specific potential difference then current must also increase B. Increasing the resistance in a circuit always decreases the potential difference across it C. If resistance is kept constant, potential difference changes directly with changes in current D. An electrical conductor's resistance depends on the potential difference it experiences

2. Fifty identical Christmas lights are connected in series and plugged into a 220V line. (Neglect wire resistance) Calculate the voltage across each light bulb. A. 2.2 V B. 4.4 V C. 110V D. 220V 3. A piece of wire connected to a 6V cell has a current of 1.5A flowing through it. What is the resistance of the wire? A. 9 ohms B. 6 ohms C. 4 ohms D. 12 ohms 4. If the voltage in the circuit were doubled, what would happen to the current in the circuit? A. current decreases twice B. current also doubled C. current decreases 4 times D. current is not affected 5. What is the voltage difference across a piece of wire of resistance 100 Ω with a current of 2A A. 5 volts B. 200 volts C. 2 volts D. 500 volts Journal Entry:

J. Additional activities for application or remediation V. REMARKS VI A. B.

C.


D.


E.


F.


G.


Let the students answer questions on the usage of electricity in the following places.


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.


C.

The learners demonstrate an understanding of current-voltageresistance relationship, electric power, electric energy and home circuitry. The learners shall be able to practice safety in handling electrical devices. S8FE – Ii-31 


II. CONTENT

Explain the advantages and disadvantages of series and parallel connections in homes.

Objectives: 1. Construct series circuit and parallel circuit. 2. Differentiate series circuit from parallel circuit. 3. Explain why household wiring and appliances usually connected in parallel. Module VI: ELECTRICITY: Lesson 30: SERIES CIRCUIT AND PARALLEL CIRCUIT CONNECTION


B.

References 1.


pp. 42 - 44

2.


pp. 61 - 33

3.

Textbook Pages

4.



Lesson Guide in Grade 8 – First Quarter pp. 121- 128

IV. PROCEDURES A.

B.



C.


D.


Identify the three basic electrical quantities and differentiate one from the other Think-Pair-Share Group students into pairs and answer the questions “What is Ohm’s Law and what is it for?” They will be tasked to explain their answer in two minutes. When you turn off one of the bulbs in your house the others remain lighted. But when you remove one bulb from a string of colored Christmas lights the other bulbs go off. Why? ( Let the teacher do the demonstration of removing the bulb of the Christmas light and the student to explain what they observed) Do the activity on Series Circuit And Parallel Circuit Connection Lesson Guide G-8 First Quarter pp. 127 - 128 Circuit I 1. What did you observe to the intensity of light as you turn the switch on?

E.


2. After inserting one bulb in the circuit, what do you notice to the brightness of the bulbs? 3. While the switch is on, what happens to the remaining bulbs after unscrewing one bulb from it? Circuit II

4. Observe the brightness of the bulb in circuit II. How do you compare the brightness of circuit I from circuit II? 5. As you add more bulbs, does the brightness of each bulb change? Why? 6. As you unscrew one bulb from circuit II, were the other bulbs affected? How does your observation compare to that in step 3? Discuss the differences between a series circuit and a parallel circuit. Summarize the lesson using the table below. Series Circuit F.

Parallel Circuit


Cite advantages and disadvantages of series and parallel connection in the following situations: G.


1. connection for Christmas light 2. streetlights connection Components of an electrical circuit or electronic circuit can be connected in many different ways. The two simplest of these are called series and parallel and occur frequently. Components connected in series are connected along a single path, so the same current flows through all of the components. Components connected in parallel are connected so the same voltage is applied to each component.

H.


A series circuit is a circuit in which resistors are arranged in a chain, so the current has only one path to take. The current is the same through each resistor. The total resistance of the circuit is found by simply adding up the resistance values of the individual resistors A parallel circuit is a circuit in which the resistors are arranged with their heads connected together, and their tails connected together. The current in a parallel circuit breaks up, with some flowing along each parallel branch and re-combining when the branches meet again. The voltage across each resistor in parallel is the same. Choose the letter of the correct answer. 1. A circuit that has only one electric flow is _________. A. parallel circuit B. battery circuit C. paper circuit D. series circuit 2. What happens to lights in series if one goes out? A. they all go out B. Every other one goes out C. they stay lit D. they flicker

I.

Evaluating Learning

3. What happens to the intensity or the brightness of the lamps connected in series as more and more lamps are added? A. increases B. decreases C. remains the same D. cannot be predicted 4. Two bulbs are connected and plugged to the outlet as shown in the figure. Both bulbs have the same.. A. current B. voltage C. resistance D. voltage and current

5. In the circuit below, which two elements are connected parallel to each other? A. A and B B. B and C C. C and D D. A and D

J. Additional activities for application or remediation V. REMARKS VI. REFLECTION A. B.

C.


D.


E.


F.


G.


Prior to the lesson, give the students a research activity. Make a comparison between George Ohm and G. R. Kirchhoff regarding their contribution in science. Find out how they were able to come up with their laws.


School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.


C.

The learners demonstrate an understanding of current-voltageresistance relationship, electric power, electric energy and home circuitry. The learners shall be able to practice safety in handling electrical devices. S8 30FE – Ii – 32 


Differentiate electrical power and electrical energy

Objectives: 1. Define (a) electrical power and (b) electrical energy 2. Relate electrical power to energy. 3. Relate power to voltage and current Module VI: ELECTRICITY: Lesson 31: ELECTRICAL POWER AND ENERGY


B.

References 1.


pp. 45

2.


pp. 54 - 55

3.

Textbook Pages

4.



EASE Physics. Module 7. Lesson 3 and 4 Science and Technology IV. Aquino, Remedios G.et.al. pp. 194-195 Science and Technology IV. IMC. Pp. 205-206 Lesson Guide in Grade 8 – First Quarter pp. 121- 128

IV. PROCEDURES A.


B.


C.


Why parallel connection is prepared over series connection? Let the students recall their monthly electric bill. Ask them what factors mostly affect the high cost of their electric bill. Energy makes an electrical appliance work. The amount of energy the appliance uses depends on the rate at which it uses energy and the length of time it is used. The rate at which an appliance uses up electrical energy is called power input. Power input is measured in watts ACTIVITY 1. Post on the board drawings of some common appliances with labels.

D.


bread toaster 2. Brainstorm ideas about the significance of the information printed on the appliances. 3. In the table given below, write down the names of the appliances and their power ratings, uses, and power effects such as light, heat, mechanical or sound. Discuss the data table.

Appliances

E.


Power Rating (w)

Use

Effects

1 2 3 4 5 6 7 8 9 10 1. What type of appliances usually have high power rating? 2. What is the importance of knowing the power rating of appliances?

F. Developing mastery (Leads to Formative Assessment 3)

3. What general statement can you make about power rating and the effects produced by electricity? 4. What is the common feature of those appliances like flat iron, toaster, stove (range) and hair dryer? 5. What is power? How is it related to energy? 6. Relate power (P) to voltage (V) and current (I).

G.


What appliances in your home contribute most to your energy consumption? What would you suggest to lessen your electrical energy consumption? Electric power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Electric power is usually produced by electric generators, but can also be supplied by sources such as electric batteries.

H.


Electrical energy is energy that is caused by moving electric charges. Since the electric charges are moving, this is a form of kinetic energy. The faster the electric charges are moving the more electrical energy they carry. The electrical energy consumed or needed in operating various devices may be related to the power rating of the devices. Recall that power is the rate at which work is done per unit time. In equation form,

Power = work/time where P = power W =work T = time

In a simple electric circuit, voltage is defined as the work done per unit charge. V = W/q Current is also defined as the amount of charge passing through a point per unit time. I = q/t Multiplying V and I, we get VI = W/q . q/t = W/t =P Therefore: P = VI In a simple electric circuit, electric power is the product of current and voltage. Hence: Power = Voltage x Current P = VI where: P = power in watts V = voltage in volts I = current in amperes Voltage and current are positively related to power. Appliance with high voltage across it, or with high current through it, it has high power or rate of converting electrical energy to other forms.

Write TRUE if the statement is true. If the statement is incorrect, change the underlined word or words to make the statement correct. 1. When the current in the circuit is doubled, the power also doubles. 2. Electrical appliances at home transfer energy from the mains supply to heat and light our homes. I.

Evaluating Learning

3. Minimizing television viewing is not a way of saving electrical energy. 4. High power rating electrical appliances give low electrical energy consumption. 5. Heating appliances like flat iron, toaster and electric stove draw more current so they convert more electrical energy than nonheating appliances.

J.




Make a list of electrical appliances/machines which used electricity in the following environment: 1. at home 2. at the hospital 3. at school 4. in the city For each item, try to think of an alternative and a way to conserve or save power.

C.


D.


E. Which of my teaching strategies worked well? Why did these worked? F.


G.



School

Grade Level

Grade 8


Learning Area

Science

Quarter

First (Physics)


Content Standards

B.


C.

The learners demonstrate an understanding of current-voltageresistance relationship, electric power, electric energy and home circuitry. The learners shall be able to practice safety in handling electrical devices. S8 30FE – Ii - 33 


Explain the functions of circuit breakers, fuses, earthing, double insulation, and other safety devices in the home.

Objective: Describe a fuse and a circuit breaker and identify their functions in a circuit

II. CONTENT

Module VI: ELECTRICITY: Lesson 32: Safety in Using Electricity: CIRCUIT PROTECTORS


B.

References 1.


pp. 45 - 46

2.


pp. 64-67

3.

Textbook Pages

4.



EASE Physics, Module 7. Lessons 3 and 4 Science and Technology IV : Physics Textbook. NISMED.2012 pp. 174 - 175

IV. PROCEDURES A.


Recall from the previous lesson electrical appliances that contain heating element.

B.


Let the students discuss among themselves the answers on the question, “What do you think is the effect of electric shock in the human body. Why is electrical safety important?

C.

D.

Presenting examples / instances of the new lesson Discussing new concepts and practicing new skills #1

How many of you have seen a fuse or a circuit breaker at home? Did you ever wonder why a fuse is needed in your electrical connections? Today we will handle a fuse and determine its function. Do the activity on Blowing a Fuse, Lesson Guide Grade 8 First Quarter pp. 136 – 137. Case 1 1. What two things were observed when the switch was closed?

E.


Case 2 1. What three things were observed when a short wire was connected as shown in the diagram? 2. What could have caused the rising and falling of current in the wire in case 2? 3. Describe the result when there was reduced resistance in the circuit. 4. Identify the case that occurred 5. Explain why the bulb went off. 6. What is the role of the fuse in the circuit?

F.


G.


Discuss the answers in the activity given. Why is it dangerous to use copper strip or wire in place of a safety fuse that blows out? Why do we need to be protected from the danger in electricity? Fuses and circuit breakers are both devices that 'break' if the current through them is too large. A fuse is usually a thin piece of wire that will melt and break the circuit if too large a current flows through it. The thicker the wire the more current is needed to melt it and the higher the 'rating' of the fuse. The purpose of a fuse is to protect the wiring and the equipment.

H.


A circuit breaker is an electronic circuit that will switch off the current if it is too great. Such a circuit is designed to operate much more quickly than a fuse and so the damage is less because the current is switched off in a much shorter time. Circuit breakers are often used to protect the user if the casing of the equipment becomes live. They break the circuit before the person using the equipment gets a near fatal shock. Grounding is a method of giving electricity the most effect way to return to the service panel. The ground wire is an additional path for electrical current to return safely to ground without danger to anyone in the event of a short circuit. In that instant, the short would cause the current to flow through the ground wire, causing a fuse to blow or a circuit breaker to trip. An ungrounded electrical box, appliance, power tool, or extension cord could become a danger if there is no path to ground, except through you. Direction: Write the word SAFE if the statement is true and DANGER if the statement is wrong. 1. Fuses and circuit breakers are both devices that 'break' if the current through them is too large. ( safe ) 2. A fuse is usually a thick piece of wire that will melt and break the circuit if too little amount of current flows through it. (danger)

I.

Evaluating Learning

3. Grounding is a method of giving electricity the most effect way to return to the service panel. (safe) 4. Electrical safety tips need to be observed frequently. (danger) 5. A properly grounded circuit has boxes, devices, and service panel grounds that give the electrical current the easiest path to ground and that reduces the chances of someone getting a shock or getting electrocuted. (safe)

J.




B.


C.


D.

No. of learners who continue to require

Make a research on Octopus Wiring.

remediation E.


F.


G.


TOPIC OUTLINE GRADE 8 - SCIENCE UNIT I. FORCE MOTION AND ENERGY Module Number I. Forces and Motion

II. Work, Power and Energy

III. Sound

IV. Colors of Light

V. Heat

VI. Electricity

Topics A. 1. Balance and Unbalanced Forces

Learning Competency Code S8 FE-Ia-15/16

B. 1. Inertia 2. Acceleration 3. Interaction C. 1. Relationship of Circular Motion and Newton’s 2nd Law of Motion A. 1. What is work? 2. Work : Method of Heat Transfer 3. Calculating the amount of work done. B. 1. Relationship among Work, Power and Energy C. 1. Kinetic Energy 2. Potential Energy

S8 FE-Ia-17

A. 1. Propagation of Sound 2. Characteristics of Sounds 3. Properties of Sounds

S8 FE – Ie - 24

A. 1. The Visible Spectrum B. 2. Dispersion of colors C. 3. Refractive Index of the Color of Light A. 1. Heat and Temperature 2. Thermal Expansion: The Working Principles of the Mercury Thermometer 3. Phase Change 4. Heat Capacity A. Ohm’s Law: Relationship among Current, voltage and Resistance a. Current and Voltage b. Current and Resistance B. Electrical Connections in homes a. Series b. Parallel C. Differences between Electrical Power and Electrical Energy

S8 FE – If - 26 S8 FE – If - 27 S8 FE – If - 28

S8 FE-Ia-18-19 S8 FE – Ic - 20 S8 FE – Ic – 21 S8 FE – Id – 22 - 23

S8 FE – Ie - 25

S8 FE – Ig - 29

S8 30FE – Ih - 30

S8 30FE – Ii - 31 S8 30FE – Ii - 32 S8 30FE – Ii - 33

D. Safety in Using Electricity

Prepared by:

ROMANA GLENDA S. LAGMAY Bayorbor National High School

OFELIA A. MENDOZA Coral na Munti National High School

Presented to the Division Facilitators/Editors of Grade 8-Science:

LORYFE A. MANALO Head Teacher III

GLICERIA A. LANDICHO Head Teacher I

Noted by:

MARIO B. MARAMOT EPS I - Science

MARCELO B. ULARTE Head Teacher III

Dll Grade 8 First Grading - Final Copy

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