An Electron Moves Through a Region of Crossed Electric and Magnetic

Multiple Choice

An electron moves through a region of crossed electric and magnetic fields.The electric field E = 3200 V/m and is directed straight down.The magnetic field B = 0.80 T and is directed to the left.For what velocity v of the electron into the paper will the electric force exactly cancel the magnetic force?

A) 2500 m/s
B) 5000 m/s
C) 4000 m/s
D) 8000 m/s