Chapter 28, Problem 43AP

A proton having an initial velocity of $20.0\hat{i}\text{Mm}/\text{s}$ enters a uniform magnetic field of magnitude 0.300 T with a direction perpendicular to the proton’s velocity. It leaves the field-filled region with velocity $-20.0\hat{j}\text{Mm}/\text{s}$. Determine (a) the direction of the magnetic field. (b) the radius of curvature of the proton’s path while in the field, (c) the distance the proton traveled in the field, and (d) the time interval during which the proton is in the field.