# A 500 kg satellite experiences a gravitational force of...

1. Dec 28, 2016

### LionLieOn

1. The problem statement, all variables and given/known data
A 500 kg satellite experiences a gravitational force of 3000 N, while moving in a circular orbit around the earth.
c) Find the Period of the orbit
2. Relevant equations
So found the period using (Please see the attachment to review my work.) but I also found it by using (V=D/T)
V= 2(Pi)r/T

I was wondering if there's any difference?

3. The attempt at a solution

#### Attached Files:

• ###### FCFG.jpg
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2. Dec 28, 2016

### ehild

Your result is correct, and after getting V from the centripetal force, you can calculate T from V= 2(Pi)r/T.

3. Dec 29, 2016

### LionLieOn

So either 1 is fine?

4. Dec 29, 2016

### ehild

Yes, either one. And there is an even simpler method to calculate the period.
You have two equations, one for Fc in terms of ω, $Fc=mrω^2$ and one for Fg $Fg=G\frac{mM}{r^2}$, : with Fc=Fg=3000 and m=500.
Isolate r from one of them and substitute the expression for r into the other equation. No need to calculate the numerical value of r. You get the simple formula $ω^2=\frac{6^3}{GM}$

5. Dec 30, 2016

### LionLieOn

Ahh! Ok. Thank you so much for your help :)