Question

The Earth and the Moon may be considered to be uniform spheres that are isolated in space. The Earth has radius R and mean density ρ. The Moon, mass m, is in a circular orbit about the Earth with radius nR, as illustrated in Fig. 1.1. Moon Earth radius R nR Fig. 1.1 The Moon makes one complete orbit of the Earth in time T. Show that the mean density ρ of the Earth is given by the expression ρ = 3πn3 GT

Answer 1

hope u understand the calculations yourself