# Satellite (Gravitation) Question

1. Nov 19, 2006

### Destrio

A satellite has a orbital period of 5760s around earth. What is the orbital radius?

I'm not sure how I can do this without the velocity or acceleration.

Thanks,

2. Nov 19, 2006

### neutrino

Is no other information provided in the question?

3. Nov 19, 2006

### Destrio

no other information,
however, part of the question might have been cut off

4. Nov 19, 2006

### neutrino

EDIt: Never mind...

Last edited: Nov 19, 2006
5. Nov 19, 2006

### nrqed

I assume they mean that the orbit is circular.

Then simply use
$$P = { 2 \pi R \over v}$$

and $$m { v^2 \over R} = G { m M \over R^2}$$
where M is the mass of the Earth and m is the mass of the satellite. Then you have two equations for two unknowns: R and v. Which you can then solve.

Patrick