82. A small ball of mass m = 1 g, having a charge q1 = 1 nC, is suspended on an insulating thread. Another charged small ball is brought to it from below at a distance of r = 2 cm, and the thread tension force is halved. What is the charge q2 of another ball? Wednesday is air.

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