Potential Energy

Gravitational potential energy *E*ₚ is a type of energy which is possessed by every physical body found in a gravitational field. The potential energy of a physical body in the Earth's gravitational field can be changed into kinetic energy, which can perform some mechanical work. Potential energy is relative, it depends on what it refers to. In our model situation, it refers to the level of the sand in the sandbox (level of zero potential energy). The formula for calculating the potential energy is *E*ₚ = *m*.*g*.*h*, where *m* is the mass of the physical body, *g* is the gravitational acceleration, and *h* is the height above the level of zero potential energy.

**Two bodies of the same weight falling from various heights**

The model shows two bowling balls of the same weight at different heights above the sandpit. The ball which is at a greater height has greater potential energy and therefore it performs a larger work upon impact ‒ it will sink deeper. The animation demonstrates that with increasing height the body acquires greater potential energy.

**Two bodies of different weights falling from the same height**

The animation shows two different balls of different masses at the same height. The sphere with a larger weight has also higher potential energy and therefore it performs a larger work upon impact ‒ it sinks deeper. It demonstrates that the heavier physical body acquires a greater potential energy.