Gravitational Potential Energy of a particle

1. Mar 27, 2009

peaceandlove

1. The problem statement, all variables and given/known data
Four particles, each of mass 60.0 g, form a square with an edge length of d = 0.700 m. If d is reduced to 0.100 m, what is the change in the gravitational potential energy of the four-particle system?

2. Relevant equations
U = -GMm/r

3. The attempt at a solution
I found the U of the system when d = 0.700 m and then I found the U when d = 0.100 m. Using those two values, I found what I believe to be the change in the U of the system. However, I keep getting the wrong answer.

U_1=-6.45898846e-12
U_2=-2.60012192e-11
(delta)U=1.95422308e-11

Last edited: Mar 27, 2009
2. Mar 27, 2009

peaceandlove

Nevermind, I figured it out.

Last edited: Mar 27, 2009