일반물리학 2 — Magnetic Fields: Problem 62

62 In a nuclear experiment a proton with kinetic energy 1.2 MeV moves in a circular path in a uniform magnetic field. What energy must (a) an alpha particle (q = +2e, m = 4.0 u) and (b) a deuteron (q = +e, m = 2.0 u) have if they are to circulate in the same circular path?