# Chapter 3 physics

Shell theorem statement:

The gravitational force exerted to an external mass due to an uniform thin hollow shell, behaves as if the whole of its mass is concentrated at the center of the shell. Moreover, gravitational field inside a shell is zero.

The gravitational force between M and m is given by,

F = (G.M.m)/(r^2)

The gravitational field of M at position of m is given by,

Eg = GM/r^2

The gravitational potential of M at position of m is

V = GM/r