29. In figure AA is a charged infinite plane and B is a ball of the same name with a mass of m = 0.4 mg and a charge of q = 667 pC. The tension force of the thread on which the ball hangs, T = 0.49 mN. Find the surface charge density σ on the plane AA.

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