Question

Give one example each where:
(a) a force moves a stationary body.
(b) a force stops a moving body.
(c) a force changes the speed of a moving body.
(d) a force changes the direction of a moving body.
​(e) a force changes the shape (and size) of a body.

Answer 1

(a) If we push a stationary box lying on the ground, then the box starts moving due to the action of the force.

(b) When we apply the brakes in a car, a force stops the motion of the car.

(c) If we hit a ball lying on the ground by a force, then the ball starts moving. In this case, the force changed the speed of the ball from zero to a certain value.

(d) When we tie a stone with a thread and move it around us on a circular path, then the force exerted by our hands works as a centripetal force. That force helps the stone to change its direction continuously and move on a circular path.

(e) When we blow air into a balloon, force changes the size and when we squeeze a rubber ball, the force changes the shape of the ball.