1. The problem statement, all variables and given/known data I am told that the gravitational force of a mass m located inside an isotropic distribution of spherical radius R and total mass M is given by Fg = -GmM(r)/r^2 where r is the distance between m and the center of distribution and M (r) is the mass contained below the distance r (weight between 0 and r). Suppose the sphere is homogeneous of constant density ρ= M/((4πR^3)/3) I need to find the gravitational potential energy inside the distribution as a function of M, m, R, r and G 2. Relevant equations 3. The attempt at a solution So far I have found the gravitational potential energy, but I don't know how the density is going to come into play. I also don't understand what the isotropic distribution is going to change in my answer and derivation.