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Electricity and Magnetism

  • #1
HI,

So say you have a small ball hanging vertically below a positively charged plate. When the ball is released from rest with the string at a small angle to the vertical, it swings in periodic pendulum motion. If the ball is now positively charged, does the period increase, decrease or stay the same? And why?

- Well at first, when it's neutral, there would be a slight attraction between the ball and the charged plate. But when the ball becomes positive as well, there would be now a slight repulsion. So would it stay the same?
 

Answers and Replies

  • #2
283
0
Do you know the differential equation for a simple pendulum? You could derive a similar equation with the electric force included. The solution should have the same form, so the period should be fairly obvious
 

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