Question

The planet Mars has a satellite, Deimos, which travels in an orbit of radius 2.346×107 m with a period of 1.26 days. Calculate the mass of Mars from this information.

Answer 1

Force on Deimos= centripetal force
GMm*Ms/r^2=Ms v^2/r

but v=2PIr/T and you know r and T

Solve for Mmars