# Satellite Calculations

## Homework Statement

If the space station orbits the earth 225 km above the surface , what are the satellites orbital speed and period ? The mass of the earth is 5.97 E24 kg and the radius is 6.38 E6 m.

## The Attempt at a Solution

I already have the speed ( v ) , I just don't understand how to find the orbital period

Te^2/ Re^3 = Ts^2/ Rs^3

I know the earths radius and orbital, but do I put the t in hours or seconds ?
How do I find the satellites radius ?
If anyone could help it would be appreciated.

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gneill
Mentor
I already have the speed ( v ) , I just don't understand how to find the orbital period

Te^2/ Re^3 = Ts^2/ Rs^3

I know the earths radius and orbital, but do I put the t in hours or seconds ?
Just use the correct significant figures for either.

What's Te?

How do I find the satellites radius ?
??? How did you find the speed without the orbital radius? You said you had the orbital radius.

Maybe you should show your work so far.

Well I got the orbital radius by take the 225km + 6.38 * 10^6 m .
Converting 225 km to m. I used that as the R in the problem to find the speed.

gneill
Mentor
Well I got the orbital radius by take the 225km + 6.38 * 10^6 m .
Converting 225 km to m. I used that as the R in the problem to find the speed.
I'm confused then. Apparently you have the orbital radius, yet you asked how to find it.

Well, moving on. What did you determine the speed to be?

Like 7761 m/s

gneill
Mentor
Okay, you have a speed. What is the circumference of the orbit?