Assuming earth is solid sphere of radius R and mean density p ; M = 4/3 πR3 p = Mass of earth.
The gravitational potential (V) at a point due to earth will, therefore, be the same as that due to a solid sphere.
Hence, on its surface, V = -GM/R
At a height h above the surface,
(r = R + h is the distance from the centre of the earth)
The potential energy of body of mass m, on the surface of the earth is defined as the work done, is bringing this mass m from r = ∞ to r = R, without accelerating it.
U of m at height h above the surface is:
