Physics - Old Questions

8. Two large parallel plates are separated by a distance of 5 cm. The plates have equaled but opposite charges that create an electric field in the region between the plates. An α particles (q = 3.2x10^-19C, m = 6.68x10^-27 kg) is released from the positively charged plate, and strikes the negatively charged plate 2x10^-6 sec. later. Assuming that the electric field between the plates is uniform and perpendicular to the plates, what is the strength of the electric field?