Question

Indicate whether the following are true or false. Rewrite the false statements correctly.
(a) If we apply the brakes to a moving car, it comes to rest. This shows that force can make a moving object go slower.
(b) When a force of 1 N acts on an area of 1 m² , the pressure exerted is equal to one Pascal.
(c) The foundations of high rise buildings are kept wide so that they exert less pressure on the ground and prevent the building from sinking into the ground.
(d) A boy throws a ball down from the second floor of a building. In this case, gravitational force is acting only on the ball.
(e) Friction helps us to walk more easily on a smooth, highly polished surface.
(f) An old truck tyre will cause more friction with the road than a new tyre.
(g) In the frozen northern regions of Canada, the Eskimos wear large snowshoes as that helps them to walk on freshly fallen snow.
(h) When a force acts on a large area, the pressure it exerts is more.
(i) Gravity and friction are both contact forces.

Answer 1

(a) False

If we apply the brakes to a moving car, it comes to rest. This shows that friction can make a moving object go more slowly.

(b) True

(c) True

(d) True

(e) True

(f) False

An old truck tyre will cause less friction with the road than a new tyre.

(g) True

(h) False

When a force acts on a large area, the pressure it exerts is less than if it had acted on a small area.

(i) False

Gravity is a non-contact force, whereas friction is a contact force.