Frictional Force

Friction in the axle of a bicycle wheel. Useful or Not useful?

Answer explanation

Not useful

Friction is useful or not useful?

Friction between your shoes and the floor.

• Useful

• Not useful

Cars need friction to stop.

• True

• False

Snow increases the friction between your shoes and the ground.

• True

• False

The air resistance of a car can be reduced by:

• A making the car bigger.

• B giving it a streamlined shape.

• C making the car heavier.

• D putting a roof box on it.

Which statement about air resistance is true?

• A If speed increases, air resistance decreases.

• B If speed increases, air resistance increases.

• C If speed decreases, air resistance increases.

• D Speed has no effect on air resistance.

What are the units used for measuring forces?

• A metres

• B newtons

• C kilograms

• D grams

Putting the oil on the axle of a bicycle would be

• A remain the same

• B increased

• C decreased

Air resistance and water resistance are both types of friction.

• True

• False

Forces do not always cause motion.

• True

• False