57. An electron flies into a flat capacitor, the field in which E = 6 kV / m, parallel to the plates. Find the change in the electron velocity at the time of its departure from the capacitor if the initial velocity is υ0 = 2 ∙ 107 m / s and the capacitor plate length is l = 6 cm.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)