physics forces unit

Question

An intergalactic space traveler has discovered a planet that has a mass of 6.0 x 10^23 kg. The force of gravity acting on a 2 kg mass on the surface of the planet is 960 N. What is the radius of the planet? (3 marks)

Answer 1

Let's first find the gravitational acceleration of the mass

960 = mg = 2 x g ==> g = 480 N/kg

g(R) = GM/R²

480 = 6.67430 × 10^-11 x 6 x 10²³ / (R_planet)²

Solve for R_planet, please.