# Homework Help: Synchronous Satellite problem

1. Feb 19, 2006

### dxlogan187

A rocket is used to place a synchronous satellite in orbit about the earth. What is the speed of the satellite in orbit?

I know that G= 6.67x10^-11 and the Mass of earth is 5.98x10^24 kg.

So I'm to assume that I use the equation

v= Square root of([G*M]/radius)

But I don't know how high off the ground the satellite is. I know the radius of the earth is 6.38X10^6 m, so I'd add that to how high above the earth it is to get the radius.

Thanks for your time!

2. Feb 19, 2006

### Tide

The distance from the center of the Earth is the relevant one. However, you just need to recognize that $\omega r = v$ which you could use to eliminate r from your equation.

3. Feb 19, 2006

### dxlogan187

What does the w symbol mean? Never seen that before

4. Feb 19, 2006

### Tide

It's the Greek letter "omega" and it stands for the angular frequency. You may be more familiar with it in this form:

$$\omega = \frac {2\pi}{T}$$

where T is the orbital period.