20. The distance between point charges Q1 = 4 ∙ 10-11 C and Q2 = 6 ∙ 10-11 C is equal to r = 5 cm. Calculate the value of the tension at point A, remote from the charge Q1 by a distance r1 = 4 cm, and from the charge Q2 at a distance of r2 = 3 cm.

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