(a) According to deduction of Kepler's third law and with the help of Newton's law, the law of period is given by or T2=
4π2
GM
r3 ⇒T=2π√
r3
GM
where, r is the radius of orbit and M is mass of the planet or star. As satellite is very close of the planet, thus r=R Also mass (M)= density (ρ)× volume (V) =ρ×