Satellite, magnitude/acceleration problem

[tennisman03110]

Satellites are placed in a circular orbit that is 3.59*10^7 m above surface of earth. What is the magnitude of the acceleration due to gravity at this distance? A formula to use or the work would be appreciated. Thanks.

 

[quantumdude]

Show how you started, please.

 

[tennisman03110]

I tried using F=G(m1*m2)/r^2. i didnt know the mass of the satellitle though so i was left with multple variables. I also tried using g, but that didnt work. I guess I really don't know how to start when the satellite has an unknown weight.