42. The flow of electrons moving at a speed of 4 ∙ 107 m / s flies into a flat capacitor parallel to the plates at an equal distance from them. What is the smallest voltage you need to apply to the capacitor so that the electrons do not fly out of it, if the capacitor has the following dimensions: length 5 cm, distance between the plates 1 cm.

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