22. An electrostatic field is created in a vacuum by a uniformly charged ball of radius R = 1 m. Determine the total charge of the ball if the potential difference for points lying from the center of the ball at distances r1 = 0.4 m and r2 = 0.9 m is equal to φ1 - φ2 = 120 V.

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