Friction

The force produced when one surface tries to slide over another is....

There is usually more friction between_______surfaces than________surfaces

If you rub your hands together the friction makes them cold.

True or false?

The grooves in a tyre or on the sole of a shoe is called.....

• lubricant

• skidding

• tread

Why does a car tyre have a tread?

• To make the tyre grip better when the road is dry.

• To allow water to escape from under the tyre when the road is wet.

• To make the tyre aquaplane when it rains.

When a vehicle's wheels lose grip and spin or slide on the road this is called........

• lubricant

• skidding

• aquaplane

A substance such as oil that reduces the friction between two surfaces is called....

• tread

• wear

• lubricant

Friction always opposes motion.

True or false?

• True

• False

Prehistoric people lit fires by.....

• Using the friction with two rocks

• Using the friction of match sticks

• Using the friction between sticks

Air resistance is not a form of friction.

True or false?

• True

• False