1. The problem statement, all variables and given/known data A beam of doubly ionized particles (i.e., twice the elementary charge) is accelerated across a potential difference of 2000 V in a mass spectrometer. They are then passed perpendicularly through a magnetic field of 0.085 T resulting in a radius of curvature 12.5 cm. Calculate the mass of the unknown ion. 2. Relevant equations Fc= mv2/r Fm= qvB ΔV=ΔE/q 3. The attempt at a solution We are supposed to derive a formula for q/m without velocity. I think the solution probably involves the centripetal force being equal to something but I'm not sure what. Any help would be appreciated, thank you!