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Homework Help: Help with physics question

  1. Jul 29, 2011 #1
    Help with coulumbs Law!!!

    1. The problem statement, all variables and given/known data

    Consider two point charges located on the x axis: one charge, = -10.0 C, is located at = -1.700m ; the second charge, = 30.5C , is at the origin .

    What is the net force exerted by these two charges on a third charge = 52.5C placed between and at = -1.055m ?

    Your answer may be positive or negative, depending on the direction of the force.


    2. Relevant equations



    Coulomb's law



    3. The attempt at a solution

    first i found,
    F(1on3)=k*10*10^-9*30.5*10^-9/.645^2 then,
    F(2on3)=k*52.5*10^-9*-10*10^-9/1.055^2

    then i added them , but i am gettin the wrong answer d answer shud be -2.43*10^-5 N

    can u tell me whats wrong with my working :)
     
    Last edited: Jul 29, 2011
  2. jcsd
  3. Jul 29, 2011 #2
    the charge is in nC
     
  4. Jul 30, 2011 #3
    Look at the charges you're using on F(2on3)
     
  5. Jul 30, 2011 #4
    oh i see thnks :)
     
    Last edited: Jul 30, 2011
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