1. The problem statement, all variables and given/known data What is the gravitational potential energy of a system of 8 masses of 10 kg each placed at the corners of a cube of length 0.25 meter apart. 2. Relevant equations U=-G*m1*m2/r 3. The attempt at a solution I have actually taken one particle pair at a time and sum all of their potential energy, but the answer is not quite right.