Chapter 27, Problem 27.27E

Crossed $\stackrel{\to }{\text{E}}$ and $\stackrel{\to }{\text{B}}$ Fields. A particle with initial velocity $\stackrel{\to }{{{\displaystyle \text{v}}}_0}$ = (5.85 × 10³ m/s)ĵ enters a region of uniform electric and magnetic fields. The magnetic field in the region is $\stackrel{\to }{\text{B}}$ = − (1.35T) $\hat{k}$. Calculate the magnitude and direction of the electric field in the region if the particle is to pass through undetected, for a particle of charge (a) +0.640 nC and (b) −0.320 nC. You can ignore the weight of the particle.