Potential energy is an object's energy due to its position relative to other objects or stresses within itself, among other factors.

One common example of potential energy is gravitational potential energy near Earth's surface. It is the energy an object has due to its relative position above the Earth's center. Gravitational potential energy, as shown by the formula below, is the product of mass (m), gravitational acceleration (g, on Earth = 9.8 m/s2), and height (h). Potential energy is measured in joules (kg·m2/s2).

EP = m g h

Together, potential energy and kinetic energy make up mechanical energy.

Illustration of a rollercoaster. The rollercoaster car starts on top of a ramp at a height "h", and it's mass is measured in kilograms. It starts rolling down the ramp at a velocity measured in meters per second. On top of the ramp, there is a label saying potential energy and in the middle of the ramp, another one saying kinetic energy.

Figure 1: Potential and Kinetic Energy