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Homework Help: What is the distance of the third charge?

  1. Mar 13, 2010 #1
    1. The problem statement, all variables and given/known data

    Three point charges, 3.0 [tex]\mu[/tex]c, -5.0[tex]\mu[/tex]c and 0 [tex]\mu[/tex]c.

    If the distance from point 1 (3.0) and point 2 (-5.0) is 40m, what is the distance from point 2 to point 3?

    2. Relevant equations

    coulombs law


    3. The attempt at a solution

    I don't know how to start this :(
  2. jcsd
  3. Mar 13, 2010 #2


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    The problem is not clear. Whether the third body is neutral?
    Are they in equilibrium?
  4. Mar 13, 2010 #3
    I'm not really sure since I only remembered this problem by memory :( but if the third body WAS neutral and they ARE in equilibrium, how would you answer this? :D
  5. Mar 13, 2010 #4


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    If the third body WAS neutral and they cannot be in equilibrium
  6. Mar 13, 2010 #5
    um, if that's so, is it then possible to be solved?

    I need to use this formula :D ?

    Fe = [tex]\frac{ Kq1q2 }{ r2 }[/tex]
  7. Mar 13, 2010 #6


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    No. Just think about it. If the third body is neutral, the other two would attract each other, accelerate towards each other, and eventually collide.
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