1. The problem statement, all variables and given/known data A mass spectrometer has a potential difference of 120 V applied to its accelerator plates. It is accelerating a positively charged ion that has a mass of 2.32 x 10^-26 kg. the ion then is directed into a uniform magnetic field of 0.17 T. The magnetic field is perpendicular to the direction that the particle is traveling. The radius of the circular path that the ion takes, while in the magnetic field, is 2.5 cm. with what speed does the ion enter the magnetic field? Potential difference = 120 V Mass = 2.32 x 10^-26 kg Magnetic field=0.17 T Theta=90 degrees Radius= 0.025m Charge=3.08 x 10^-19 C 2. Relevant equations 3. The attempt at a solution since it's traveling in a circular path a=v^2 / r I also am confused about the free body diagram (do you even need me to figure this question out?) edit: Is it that the magnetic force = the force of gravity or something like that?