QUARTER 4 SCIENCE LESSON 1
Name: Date:
Lesson 1 Describe Friction
Friction plays a vital role in our everyday life. Whatever we do, wherever we go, friction
is present. Even when we are sitting down, standing or holding a bottle or any
object, friction affects us. Friction occurs between the surfaces of two objects
in contact, rubbing or sliding against one another. It is sometimes considered
undesirable, yet it plays an important role in our daily activities.
Friction is a force that opposes an object’s motion resulting in the slowing down or
even
stopping the moving object. When an object is pushed, it rolls on the floor and
stopped after a few seconds. It is the friction between the object and the floor
that caused the stopping of the object.
But how does friction occur?
While the object is rolling on the floor,
the surface of the object rubs against
the surface of the floor. Friction always
acts opposite the direction of an
object’s motion. The floor exerts a
frictional force opposite the object’s
motion as shown in the figure at the
right side.
Friction does not only occur on the surfaces of solid objects rubbing against one
another, but it also occurs when air particles rub against objects falling down, thrown
upward and flying airplanes and kites. The force that oppos es the movement of objects
in air is called air friction or air resistance.
QUARTER 4 SCIENCE LESSON 1
Name: Date:
A. Read the following items carefully and tell whether the statements are True or False.
On your answer sheet, write True if the statement is correct and False if the statement
is incorrect.
________1. Friction acts in a direction the same as the direction of the object’s motion.
________2. Friction occurs when the surfaces of the two objects rub against each other.
________3. Friction causes moving objects to stop.
________4. Friction is produced by a single object.
________5. Friction opposes motion of objects.
B. Complete the following statements by choosing the word that best completes the
following sentences. Write the words you have chosen on your answer sheet.
I have learned that:
1. Friction is a (force, energy) that opposes the motion of objects.
2. When two surfaces of two objects rub against each other, (friction, mass) exists.
3. Friction always acts (opposite, the same) the direction of the object’s motion.
4. With friction we can do many things like: (choose as many correct examples)
speaking on a phone walking properly
holding an apple listening to a radio
sitting on a chair
C. Directions: Write “MF” if more friction or “LF” if less friction is needed on the
following activities or objects. Write your answers on your answer sheet.
1. walking a smooth surface 6. holding a glass of water
2. writing on a paper-covered surface 7. pushing a heavy cabinet
3. skating 8. rotating gears of bicycle
4. grinding 9. pole climbing
5. sliding door 10. glass and plates on top of a table
D. Complete the following statements by filling in the blanks with the appropriate
words listed inside the given box. Write your answers on your answer sheet.
I have learned that:
friction greater slows lesser
1. __________ affects the movement of objects.
2. Friction __________ the movement of objects in motion.
3. Friction is __________ in rough surface and object with bigger surface area.
4. Friction is __________ in smooth surface and object with smaller surface area.
QUARTER 4 SCIENCE LESSON 1
F. Choose the letter of the correct answer.
1. A ball rolled after being kicked and slowed down until it stopped. Which of the
following forces caused the ball to slow down?
A. electrical B. friction C. gravity D. magnetic
2. Is friction between the floor and a cabinet present when a person pushes the cabinet?
A. Yes, because the bottom surface of the cabinet is in contact with the floor.
B. Yes, because the bottom surface of the cabinet does not rub against the floor.
C. No, because the bottom surface of the cabinet has nothing to do with the floor.
D. No, because the bottom surface of the cabinet is only rubbing against the floor.
3. Which of the following is NOT TRUE about friction?
A. Friction opposes motion of objects.
B. Friction occurs between non-rubbing surfaces.
C. Friction causes moving objects to slow down and stop.
D. Friction acts in a direction opposite to the direction of an object’s motion.
4. Which of the following can friction do to a glass of water on a table?
A. It moves the glass. B. It allows the glass to slide.
C. It does not affect the glass. D. It prevents the glass from sliding.
5. Study the diagram, which force does B represents?
A. friction B. gravity C. magnetic D. motion
6. The boy in the illustration pulls a stroller. Using the directions shown, which direction does the
frictional force act?
A. East B. North C. South D. West
7. Which of the following actions is difficult to do with
friction?
A. writing on a paper B. holding a banana
C. playing basketball D. pushing a heavy cabinet
8. Which of the following statements is TRUE?
A. Friction makes objects move. B. Friction stops moving objects.
C. Friction has no effect on moving objects. D. Friction allows moving object to continue
moving.
9. Which of the following statements describe friction?
A. It slows down motion. B. It pulls objects downward.
C. It does not oppose motion. D. It moves along with the object.
QUARTER 4 SCIENCE LESSON 1
10.Which force is present when two objects rub against each other?
A. friction B. gravity C. magnetic D. motion
