60. Two balls of the same radius and mass are suspended on threads of the same length so that their surfaces are in contact. What charge q needs to be reported to the balls so that the tension force of the threads becomes T = 98 mN? The distance from the center of the ball to the suspension point l = 10 cm; the mass of each ball is m = 5 g.

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