A satellite circles a spherical planet of unknown mass in a circular orbit of radius 1.9 x 10^7 m. The magnitude of the gravitational force exerted on the satellite by the planet is 140 N.
(A) What would be the magnitude of the gravitational force exerted on the satellite by the planet if the radius of the orbit were increased to 3.6 x 10^7 m?
(B) If the satellite circles the planet once every 2.1 h in the larger orbit, what is the mass of the planet?