1. The problem statement, all variables and given/known data A proton (mass mp), a deutron (m=2mp, Q = e), and an alpha particle (m = 4mp, Q = 2e) are accelerated by the same potential difference V and then enter a uniform magnetic field B, where they move in circular paths perpendicular to B. Determine the radius of the paths for the deuteron and alpha particle in terms of that for the proton. 2. Relevant equations r = mv/qB r= radius m=mass v=velocity q=charge B=magnetic field 3. The attempt at a solution I thought V = delta PE = delta KE = delta (1/2)mv2 And then I got confused.