At t = 0 an electron crosses the positive y-axis (so x = 0) at 42 cm from the origin with velocity 4. 105 m/s in the positive x-direction. It is in a uniform magnetic field.
(a) Find the magnitude and the direction of the magnetic field that will cause the electron to cross the x-axis at x = 42 cm.
(b) What work is done on the electron during this motion?
(c) How long will the trip take from y-axis to x-axis?