Worksheet 14

s

Activity:

Tick the correct answers.

Friction can be reduced by:

using wheels( )

using anti-slip mats ( )

using air cushions ( )

using talcum powder ( )

using oil, wax or grease ( )

sanding surfaces to make them smooth ( )

using rollers or ball bearings ( )

using patterns on soles of shoes ( )

using rubber pads or knobs( )

using engine oil to lubricate engines ( )

Evaluation:

Circle the correct answers.

1. Which of the following slows down the speed of a moving car?

I. The tread on tyres

II. Lubricating the car engine

III. A rough and dry road surface

IV. A wet and slippery road surface

A. I and II C. II and IV

B. I and III D. III and IV

2. Which of the following surfaces produces the greatest friction when an object moves across it?

A. Wet surface

B. Oily surface

C. Rough surface

D. Slippery surface

3. Which of the following items can help to reduce friction?

I. Lubricants

II. Air cushion

III. Rubber pads

IV. Ball bearings

A. I, II and IV C. II, III and IV

B. I, II and III D. I, II, III and IV

Choose True or False for the statements below.

1. Friction can be increased by smoothening the surfaces in contact.

True

False

2. Friction is reduced by using rollers and ball bearings.

True

False

3. Talcum powder is used to reduce friction between carom disks and the carom board.

True

False

4. Without friction, we can light up a match.

True

False

5. Rubber materials have less friction than metal materials.

True

False