1. The problem statement, all variables and given/known data A particle with a mass m and a charge Q is accelerated through a potential difference V, causing its kinetic energy to increase by an amount K. Another particle of mass m/5 and charge 2Q is accelerated through the same potential. How much kinetic energy does this second particle gain? 2. Relevant equations Vq = U (1/2)mv^2 = U; 3. The attempt at a solution I can't find an equation that relates mass, charge and kinetic energy. Any help would be appreciated.