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About Coulomb experiment

  1. Dec 8, 2015 #1
    Coulomb experiment torsion balance.

    I know that electrical force is inversely to the square of the separation r ...My question is why we take r square? why we need square? And another question, why Q1Q2(multiplication of charges) is proportional to electrical force? (why we need to multiply them?) I know it sounds like silly question..but I really want to know (my teacher didn't tell me anything .he told me "just remember the formular" )

    Thank you in advance! :D
    Last edited: Dec 8, 2015
  2. jcsd
  3. Dec 8, 2015 #2

    Vanadium 50

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    The answer is because if we measure the force as a function of distance it is proportional to 1/r^2. Similarly if we measure the force as a function of charge it is proportional to q. Since we want the equations to match reality, that's what they look like.
  4. Dec 9, 2015 #3
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