Question

Ifearth is a homogenous solid sphere of mass M and
radius R, then gravitational self potential energy of
earth is​

Answer 1

Answer:

The PE is given by the integrating the gravitational potential energy over all points in the sphere.

U=−∫R0G(4/3πer^3)(4πr^2edr)/r

=−16/3π^2Ge^2∫R0r^4dr

=−16/15π^2e^2GR^5

G is the gravitational constant,now m=4/3πR^3e

So, U=−3Gm^2 / 5R