Show that the total mechanical energy of a satellite (mass m) orbiting a distance r from the center of the Earth (mass M-e)is:

Question

-(1/2)*(G m M-e)/(r
if U = 0 at r = infinity.
Show that although friction causes the value of E to decrease slowly, the kinetic energy must actually increase if the orbit remains a circle.

I was looking at this for hours, can't quite figure out where the (1/2) comes from . . . Give me a push or the answer.

Answer 1

Ok, I will bite: what is e?

Answer 2

e is energy I believe.

Answer 3

M-e would be mass of earth.