1. The problem statement, all variables and given/known data Suppose the resonant frequency is f = 1.47×1010 s−1; that is, the electron period of revolution is T = 6.80×10-11 s. What is the corresponding strength of the magnetic field? 2. Relevant equations qvb=mv2/r qb=mv/r 3. The attempt at a solution 1.6E-19*b=9.1E-31*v/r I understand the general idea, to figure out b, but I don't understand how to figure out Velocity or Radius from the frequency/period. Can someone give me a point in the right direction?