Question

What is the gravitational potential energy?

Answer 1

Gravitational energy is the energy that is possessed by the object in the gravitational field by the virtue of its position. The potential energy at a certain height is equal to the work required to bring the mass from infinity with constant velocity to that height.

The gravitational potential energy near a planet is negative since gravity does positive work.

$U=\frac{-GmM}{r}$

This form of gravitational potential energy is used in calculating the escape velocity.