66. An electrostatic field is created by a point charge Q = 20 nC. Determine: 1) the work done by the forces of this field when the charge is moved Q1 = 10 nC from a point with a potential of φ1 = 500 V to a point with a potential of φ2 = 200 V; 2) the distance between these points.

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