A very massive star with an M mass has a geometric shape of a sphere hollow, where the mass is distributed on the surface only with the radius R. Determine the gravitational potential inside (r < R) and outside (r > R), where r is radial distance from the center of the star. (Hint: You can use Gauss's Law to gravitational field).

A very massive star with an M mass has a geometric shape of a sphere hollow, where the mass is distributed on the surface only with the radius R. Determine the gravitational potential inside (r < R) and outside (r > R), where r is radial distance from the center of the star. (Hint: You can use Gauss's Law to gravitational field).