In the figure, a proton is projected horizontally midway between two parallel plates that are separated by 0.3 cm. The electrical field due to the plates has magnitude 4.5×105 N/C between the plates away from the edges. If the plates are 4.4 cm long, find the minimum speed of the proton if it just misses the lower plate as it emerges from the field. (e = 1.60 × 10-19 C, ? 0 = 8.85 × 10-12 C2/N · m2, m el = 9.11 × 10-31 kg).