1. The problem statement, all variables and given/known data If a positron (or electron antiparticle) beam is accelerated across a potential of 20 kV, find the final velocity v of the particles. Do this problem TWICE, once using MKS units (J for energy) and a second time using "modern" units (eV for energy). Use the following values for the positron's mass: 9.11 *10-31 kg or 0.511 MeV/c^2. 2. Relevant equations E = gamma * m * c^2 E = (V2 - V1)*q 3. The attempt at a solution I set the two equations above equal to each other. Gamma is a function of v, which ends up being the only unknown. Solving for v using units of Joules and kg gives an imaginary solution, however. I'm not sure how else I would go about doing this.