# How to calculate g (geosync orbit)

1. Oct 3, 2012

### GreatEscapist

1. The problem statement, all variables and given/known data

Communications satellites are placed in a circular orbit where they stay directly over a fixed point on the equator as the earth rotates. These are called geosynchronous orbits. The altitude of a geosynchronous orbit is 3.58e7 m.

2. Relevant equations

v=2∏r/T

a=(v^2)/r

3. The attempt at a solution

In the previous problem, I was asked to calculate the period of the satellite, which is obviously 24 hours.

I figure that g is another form of radial acceleration (both point to the center of earth).

Therefore, I calculated v using the period equation. Once I got v I used the radial acceleration equation to arrive at my answer for g.

It's wrong though- can anyone explain why and set me on the right track?

2. Oct 3, 2012

### voko

Your method is correct. It must be some numeric mistake that you made.

3. Oct 3, 2012

### Cbray

Did you add on the radius of the earth to the orbit?