Question

Why is the gravitational potential energy of two masses negative? Note that saying “because that’s what the equation gives” is not an explanation.

Short answer

If two masses are placed at infinite distance their Gravitational potential energy is Zero.

This means the negative potential energy has less potential energy than their potential energy at infinite separation.

Step-by-step solution

Given Information

Potential energy of two masses negative

Explanation

If two masses are placed at infinite distance their Gravitational potential energy is Zero.

This means the negative potential energy has less potential energy than their potential energy at infinite separation.

The gravitational potential energy is given by

$U=\frac{G{m}_1{m}_2}{r}$

When r approaches to infinity the value of potential energy approach to 0.

This means two masses infinitely far apart will have no tendency, or potential to move together.