# Potential Energy Between Two Point Masses and System of Point Masses

Physics

## definition

### Gravitational Potential Energy between two point masses

Definition: Gravitational potential energy is energy an object possesses because of its position in a gravitational field. The most common use of gravitational potential energy is for an object near the surface of the Earth where the gravitational acceleration can be assumed to be constant at about . Since the zero of gravitational potential energy can be chosen at any point (like the choice of the zero of a coordinate system), the potential energy at a height h above that point is equal to the work which would be required to lift the object to that height with no net change in kinetic energy.

Two masses and separated at a distance has potential energy:

## example

### Gravitational Energy of a System

Example: A planet of mass revloves round the sun of mass  . The distance between the sun and the planet is . Considering the motion of the sun find the total energy of the system assuming the orbits to be circular.

Solution:
Velocity of planet is
And the total energy is