An electron in a cathode-ray beam passes between 2.5cm long parallel-plate electrodes that are 6.0mm apart. a 2.1mt, 2.5-cm-wide magnetic field isperpendicular to the electric field between the plates. the electron passes through the electrodes without being deflected if the potential difference between the plates is 700v.

part a: what is the electron's speed? (express your answer to two significant figures and include the appropriate units.)

part b: if the potential difference between the plates is set to zero, what is the electron's radius of curvature in the magnetic field? (express your answer to two significant figures and include the appropriate units.)