Gravitational energy

The gravitational force near the Earth's surface varies very little with the height, h, and is equal to the mass, m, multiplied by the gravitational acceleration, g = 9.81 m/s². In these cases, the gravitational potential energy is given by

E_p,g = mgh

A more general expression for the potential energy due to Newtonian gravitation between two bodies of masses m₁ and m₂, useful in astronomy, is

,

where r is the separation between the two bodies and G is the gravitational constant, 6.6742(10)×10⁻¹¹ m³kg⁻¹s⁻².^[19] In this case, the reference point is the infinite separation of the two bodies.