12. [0/4 Points] PREVIOUS ANSWERS BAUERPHYSZ 27.P.063. At t = 0 an electron crosses the positive yaxis (50 X = 0) at 70 cm from the origin with velocity 4 x 105 m/s in the positive xdirection. It is in a uniform magnetic field. (a) Find the magnitude and the direction of the magnetic eld that will cause the electron to cross the x-axis at x = 70 cm. magnitude 3259-06 direction +x 6 x (b) What work is done on the electron during this motion? 0 (c) How long will the trip take from yaxis to x-axis? 276-06 Viewina Saved Work Revert to Last Resaonse 11 . [0/4 Points] DETAILS PREVIOUS ANSWERS BAUERPHYSZ 27.P.069. MY NOTES PRACTICE ANOTHER A proton enters the region between the two plates shown in the figure moving in the x-direction with a speed v = 1.58 x 106 m/s. The potential of the top plate is Vt = 195 V, and the potential of the bottom plate is Vb = 0 V. What are the direction and the magnitude of the magnetic eld, E, that is required between the plates for the proton to continue traveling in a straight line in the Xdirection? (Let d = 35.0 mm.) 3: (0.00288); x T V d 0) Proton Vb