Question

What happens to the potential energy when an object
(a) Falls towards the surface of the earth.
(b) The height of the body moves away from the surface of the earth.
(c) A body lying on the surface of the earth.

Answer 1

(a) 1.Potential energy is relative to a certain point.

2. When an object falls towards the surface of the earth the potential energy decreases and kinetic energy increases.

3. As the object touches the ground all its potential energy is converted into kinetic energy.

(b) The potential energy increases as the body moves away from the surface of the earth since potential energy is equal to mgh.

(c) The potential energy of a body lying on the surface of the earth is taken as zero as there is no height.