Posted by Dylan on .
A satellite has a mass of 6000 kg and is in a circular orbit 3.30 105 m above the surface of a planet. The period of the orbit is two hours. The radius of the planet is 4.20 106 m. What is the true weight of the satellite when it is at rest on the planet's surface?
I know I'm supposed to use g=Gm1m2/R^2 and r=Gm1/v^2 but I keep getting it wrong.

Physics 
bobpursley,
your g formula is most wrong.
centripetal force= gravitationalforce
m*v^2/r=G*Me*m/(radplanet+ heightabove)^2
now, note you do not need the mass of the satellite, however, you need the mass of the Planet.
velociy= 2PI (radplanet+heightabove)/period