A proton, mass 1.67 x 10^-27 kg, is projected horizontally midway between two parallel plates that are separated by 0.30 cm, with an electrical field with magnitude 520 N/C between the plates. If the plates are 4.10 cm long, find minimum speed of the proton that just misses the lower plate as it emerges from the field. Neglect the effect of gravitational force.