Worksheet 13

Activity:

Choose the correct answers.

1. When two rough surfaces come into contact, there is ________ friction.

( less , more )

2. Heavy objects produce __________ friction than lighter objects.

( less , more )

3. When two _________ surfaces are in contact, there is very little friction.

( smooth , rough )

4. Dry surfaces produce ________ friction than wet surfaces..

( less , more )

5. It is easier to open the jar lid when the hands are _______.

( dry , wet )

6. When we rub our palms together, the palms become warmer because friction

produces _________.

( heat , motion )

7. A rough surface produces ______ friction than a smooth surface.

( less , more )

Evaluation:

Circle the correct answers.

1. Which of the following factors do not affect friction?

I. Type of surfaces

II. Mass of an object

III. Shape of an object

IV. Direction of surfaces

A. I and II

B. I and III

C. III and IV

D. II and IV

2. Which activity does not involve frictional force?

A. Holding a cup

B. Singing a song

C. Stopping a car by the roadside

D. Walking on a ground without falling

3. Which of the following statements are true about friction?

I. It produces heat

II. It causes wear and tear

III. It opposes the motion of an object

IV. Wet surfaces produce more friction than dry surfaces

A. I, II and III

B. I, III and IV

C. II, III and IV

D. I, II, III and IV

Fill in the correct answer.

1. Friction produces ___________ and causes wear and tear.

2. Friction causes ____________ object difficult to move.

3. Dry surfaces produce ____________ friction than wet surfaces.

4. Friction depends on the types of the _____________ that are in contact.

Choose True or False for the statements below.

1. A smooth surface has more friction while a rough surface has less friction.

True

False

2. A heavy object is more difficult to move than a lighter object because there is

less friction.

True

False

3. It is easier to pull a luggage on a rough surface than on a smooth surface.

True

False

4. Lighter objects produce less friction than heavy objects.

True

False

5. When two rough surfaces come into contact, there is more friction.

True

False