# Changes

The formula of for gravitational potential energy for two point masses is::$E_V = -\mathrm frac{potGMm} = {r}$ where:$G$ is Newton's [[gravitational constant]]:$M$ and $m$ are the [[mass (science)|masses]] of the two particles:$r$ is their separation If one particle moves a radial distance (towards or away) from the other a distance $\Delta h$ and $\Delta h \ll r$, g then the change in potential $\Delta E$ can be approximated by :$\Delta E = mg \, \Delta h$ where $g$ is the gravitational field strength in the vicinity of the initial and final points.