1. The problem statement, all variables and given/known data I just came up with this seemingly simple problem today, but am having the hardest time solving it: Two point charges of +Q and -Q lie a distance R from each other. How long will it take for them to meet? 2. Relevant equations F = (q1*q2)/(4*pi*Eo*r^2) = ma a = dv/dt 3. The attempt at a solution So the instantaneous force on both particles will be: (Q^2)/(4*pi*Eo*r^2) towards one another. The instantaneous acceleration will be this force divided by the mass of an electron. From there you can find instantaneous velocity, but I don't know if that helps any. I just can't figure out what it is I need to integrate. Thanks in advance!