Solving a problem in physics section 72 point 45 electr

45. An electron moving at a speed of υox = 4.5 Mm / s flies into the space between two plates at an equal distance from them. The length of the capacitor plates is l = 7 cm; the distance between the plates is d = 2 cm. The voltage U = 6 V is applied to the capacitor. How much will the electron speed increase when it leaves the capacitor compared to the initial one?