55. The point charges q1 = 2 · 10−8 C and q2 = 10−8 C are located in kerosene (ε = 2.1) at a distance of r1 = 0.04 m from each other. What work must be done to bring charges closer to a distance of r2 = 0.02 m?

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