Solving a problem in physics section 73 point 91 electr

Solving a problem in physics section 73 point 91 electr

91. A small ball weighing 0.4 g is suspended on a thin silk thread and has a charge of 4 ∙ 10−7 C. What is the distance from below to bring another ball with the same charge of 6 − 10−8 C, so that the thread tension becomes half as much?

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