How Is Work Done by Gravitational Force Calculated in Satellite Orbits?

[emmah01]

1. Homework Statement

A 7655 kg satellite has an elliptical orbit. The point on the orbit that is farthest from the Earth is called the apogee and is at the far right side of the drawing. The point on the orbit that is closest to the Earth is called the perigee and is at the far left side of the drawing. Suppose that the speed of the satellite is 2880 m/s at the apogee and 8396 m/s at the perigee. Find the work done by the gravitational force when the satellite moves from a) the apogee to the perigee and b) the perigee to the apogee?

2. Homework Equations

No idea...

The Attempt at a Solution

Honestly I don't even have a clue how to start this...anyone who can help, thank you!

Homework Statement

2. Homework Equations
3. The Attempt at a Solution

 

[voko]

What is 'work'? Have you heard of the 'word-energy theorem'?

 

[phinds]

Honestly I don't even have a clue how to start this...

That being the case I have to ask, why are you even trying it? If it is part of a class you should have SOME idea how to start it.