A pаir оf chаrged cоnducting plаtes prоduces a uniform field of 12,000 N/C, directed to the right, between the plates. The separation of the plates is 40 mm. An electron is projected from plate A, directly toward plate B, with an initial velocity of vo = [v] × 10[n] m/s, as shown in the figure. How close to plate B does the electron get before it begins moving in the opposite direction? Give your answer in mm. Do not include the units. (qe = 1.60 × 10-19 C, ε0 = 8.85 × 10-12 C2/N ∙ m2, mel = 9.11 × 10-31 kg)