[SOLVED] Magnetism question 1. The problem statement, all variables and given/known data A proton, a deuteron and an alpha particle with the same kinetic energies enter a region of uniform magnetic field, moving at right angles to B. Compare the radii of their circular paths. 2. Relevant equations v = qBR / m 3. The attempt at a solution Using the equation above: K (kinetic energy) = [(q^2)(B^2)(R^2)] / 2m so (R^2) = (2mK) / [(q^2)(B^2)] From here, I don't know what to do... How do I compare the radii?