Here is the problem: Point A is at a potential of +250 V, and Point B is at a potential of -150 V. An alpha particle is a helium nucleus that contains two protons and two neutrons; the neutrons are electrically neutral. An alpha particle starts from rest at A and accelerates toward B. When the alpha particle arrives at point B, what kinetic energy( in electron volts) does it have? So here is what I know: alpha particle +2 charge and atomic mass of 4. KE=1/2mv^2. I know that E=KE + PE and E final = E initial. I am going around in circles with this one any advice on where to begin?