94. On the surface of two concentric conducting spheres with radii R1 = 5 cm and R2 = 10 cm, a certain charge is uniformly distributed (with the same surface density σ). Find the charge Q, if to transfer a positive charge Q0 = 1 C from infinity to the center of the spheres, it is necessary to do the work A = 3 kJ.

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