Energy of a Binary System (Gravitation)

[somebody8888]

Homework Statement

What is the kinetic energy and total mechanical energy of a binary system of identical spheres orbiting around their common center of mass?
M = mass
R = radius

Homework Equations

Force of gravity = GM^2/2R
K = 1/2MV^2

The Attempt at a Solution

I don't know whether or not you double the kinetic energy since there are two spheres.

 

[aim1732]

Of course you would have to add the K.E of the two spheres for the total K.E.
And your eqn. for force is wrong??