Posted by g on Tuesday, December 18, 2012 at 7:59pm.
Determine the magnitude and direction of the gravitational force exerted a) on the Moon by Earth and b) on Earth by Moon.

Phsyics  drwls, Tuesday, December 18, 2012 at 10:51pm
The forces are the same, but in opposite directions. The Earth pulls the moon and vice versa.
The force is G*M*m/R^2
G = universaL constant of gravity
m = lunar mass
M = Earth mass
R = earthmoon separation
The force also equals m*V^2/R
where V is the velocity of the moon its orbit. 
Phsyics  g, Thursday, December 20, 2012 at 3:49pm
I did not get the answer...