Got a doosie here, Angular acceleration, time and radius.

1. Oct 5, 2011

GRice40

1. The problem statement, all variables and given/known data
An earth satellite moves in a circular orbit with an orbital speed of 6200 m/s. Find the time of one rotation as well as the radial acceleration of the satellite in orbit.

2. Relevant equations
Ac= V^2/R
mAc=mg
V= 2(pi)R/t

3. The attempt at a solution

Ok, I've gone every which way I can with this problem. I don't know how to go about it. I've drawn an FBD and the only forces I can see acting on it are the weight of the satellite and the Ac. I don't know if there is supposed to be another variable that is assumed, like the radius of the earth, or if gravity acts upon the satellite at 9.8 m/s^2 like it would on earth...I'm pretty lost here. Any advice on how to start?

2. Oct 5, 2011

flyingpig

I believe the orbital speed is the tangential speed of the satellite.

What is one rotation? (quickly, go back to your unit circle!)

3. Oct 5, 2011

GRice40

One rotation is 2(pi) radians, iirc.

4. Oct 5, 2011

GRice40

I still don't know where to go from there, it seems like I need another variable somehow...