Gravitational Potential Energy

Definition and Basics

Gravitational potential energy denotes the energy held by an object because of its position relative to other objects, stresses within itself, electric charge, and other factors.
It’s a form of potential energy, which is energy that is stored in a system or in an object due to its configuration or position.
It is experienced between two objects due to their mass and the distance between them.

To calculate the gravitational potential energy of an object near the surface of the Earth, the commonly used formula is gravitational potential energy = mass (m) X gravity (g) X height (h).
The value of gravity (g) is approximately 9.8 m/s^2 on Earth’s surface.
In this equation, the mass and height should be in kilograms and metres, respectively, and the resulting energy will be in joules (J).

Gravitational potential energy increases with increased height and mass. So, a heavier object or an object at a greater height will have more gravitational potential energy.
The gravitational potential energy of an object is zero at ground level because the height is zero at this position.
When an object falls, its gravitational potential energy is converted into kinetic energy until, upon impact with the ground, all the gravitational potential energy has been converted to kinetic energy.

The gravitational potential energy also corresponds to the work done in moving the object from a reference point (usually taking as ground level or where height is zero) to the height ‘h’, against gravity.
This work done is equal to the force (weight of the object) times the distance (height it was moved), which in essence is the gravitational potential energy.
Therefore, the gravitational potential energy can be thought of as the work done to elevate objects against Earth’s gravity.

There are several real-life applications of gravitational potential energy, such as in hydroelectric power stations where gravitational potential energy is converted into electrical energy.
Another example includes the use of pulley systems in construction sites where the lifting of heavy objects involves the conversion between gravitational potential energy and kinetic energy.
Most sports also involve the transfer of gravitational potential energy into kinetic energy. For example, when a football is kicked high into the air, it gains gravitational potential energy, which is converted to kinetic energy as it comes back down.