I understand that, but in order to calculate the kinetic energy of the particles, I need to know the speed of the other particle as well, because energy is conserved, which isn't given, so I'm not sure what to do after that. Also, if I'm not mistaken, mass doesn't affect the potential difference...
Homework Statement
One particle has a mass of 3.00 10-3 kg and a charge of +7.50 µC. A second particle has a mass of 6.00 10-3 kg and the same charge. The two particles are initially held in place and then released. The particles fly apart, and when the separation between them is 0.100 m...