An ion with a mass m and a magnitude of charge of 1e is initially at rest when it is accelerated by a potential difference of magnitude AV. After exiting the accelerating potential, it enters a region with a uniform magnetic field perpendicular to the ion's velocity. The ion moves in a semicircle of radius R.
Next, an ion with a mass m' and a magnitude of charge of 4e is accelerated by the same potential difference and deflected by the same magnetic field. The radius of its semicircular path is R' = 6R. Find the ratio of the ion masses, m'/m. Note that the ratio depends on the charge. Did you neglect to include the factor of the new charge when finding the ratio?