A singly charged ion of mass m is accelerated from rest by a potential difference ΔV. It is then deflected by a uniform magnetic field (perpendicular to the ion's velocity) into a semicircle of radius R. Now a triply charged ion of mass m' is accelerated through the similar potential difference and deflected by the same magnetic field into a semicircle of radius R' =4R. Determine the ratio of the masses of the ions?