A satellite has a mass of 5600 kg and is in a circular orbit 3.70*10^5 m above the surface of a planet. The period of the orbit is two hours. The radius of the planet is 4.20*10^6 m. What is the true weight of the satellite when it is at rest on the planet's surface?

2 answers

Inorbit?

ForceGravity=centripetal force
GMm/(3.7E5+4.6E6)^2=mv^2/r

but v= 2PIr/T
= m 4PI^2*(4.6E6+3.7E5)/T

solve for GM

Now, with GM known,

weight at the surface= m*GM/(4.2E6)^2
where did you get 4.6*10^6?