A 1000 kg satellite travels with an orbital speed of 500 m/s around a planet at an orbital radius of 8000 km. What is the mass of the planet?

The satellite revolves in a circular orbit and has a centripetal acceleration. This centripetal acceleration is caused by the gravitational attraction force of the planet.

m = mass of satellite M mass of planet R radius of the orbit

V linear velocity tangential to the orbit G = gravitational constant

Centripetal force = m V² / R

= gRGravitational Force = G Mm / R²

So, V² = G M/R

So, M = V² R / G = 500² * 8000 * 1000 / 6.67 * 10^-11

= 2.998 * 10^22 Kg