A satellite moves in a low circular orbit about a spherical earth that has no atmosphere (it barely skims the surface of the earth). Approximately how many minutes will it take the satellite to make one revolution around the earth?

 

I think you would use Kepler's third law here, but there are no numbers and the answer choices are 80,82,84, and 86 minutes.

How do you do this?

It's circular motion, meaning the gravitational force is a centripetal force.

 

You're told it's earth rather than some random planet, so you can probably use known earth values in the problem.

Oh okay, that worked for me, just didn't realize I should've used the earth constants. Thanks.