Calculating Satellite Orbit Time

[a.k]

Homework Statement

The average speed of an orbiting satellite is 20,000 mph. How much time is required for the satellite to orbit Earth? (the satellite is orbiting 250 miles above the Earth’s surface, and remember that the Earth has a radius of 3,963 miles.)

Homework Equations

t=d/v
2∏(r)

The Attempt at a Solution

3963+250=4213

2∏(4213)
6.28(4213)
26457.84 miles

26457.64/20000
=1.32 hours*60mins
=79.2 mins

Did I do this correctly?

 

[nasu]

It looks OK.

 

[a.k]

Thank you for the response.

 

[vanceEE]

I don't see anything wrong. But, for the future; try to keep exact, or near exact answers throughout your problem, for example, when you multiplied $6.28$ by $4213$ you got $26457.84$mi, whereas the exact answer was $8426\pi$mi or $26471.0597$mi. Besides that I don't see anything wrong with your solution.