1. The problem statement, all variables and given/known data A square of side s has a point charge at each corner. They all have the same charge +q, but different masses, m1, m2, m3, and m4, respectively. Initially, all of the charges are held at rest until they are released. Of course, they would repel each other and move away from each other until they are very very far. What is their final velocities at infinity (i.e. a long long time after they are released)? 2. Relevant equations Ui=kq1q2/r KE=(1/2)mv2 3. The attempt at a solution I know that the initial electric potential energy of the system is: U=(kq2/s)(4+sqrt(2)) To conserve energy, I know that this should also be the total kinetic energy of the system at infinity. Now, I don't know how to divide the kinetic energy among the charges. If I do this, I can get the final velocity using KE=(1/2)mv2. Am I correct? Can you give any hints on how to divide the kinetic energy? Should I just divide it equally?