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Homework Help: E-feild and stuff

  1. Jan 19, 2004 #1
    I really need help, and I'd greatly appreciate it.

    "Two point charges of +10nC and -20nC lie on the x-axis at points x=0 and x=+10m, respectavly. Find the point where the net electric feild is zero, if such a point exists."

    The teacher gave us the answer 24m, and I just can't see how!!!

    You help is REALLY APPRECIATED, I have been on this one forver it seems...

    I keep getting 20m?
     
    Last edited by a moderator: Jan 19, 2004
  2. jcsd
  3. Jan 19, 2004 #2
    Show your solution sheet where u got 20 m

    24m is correct
     
  4. Jan 19, 2004 #3
    I did

    k*10nC     k(-20nC)
    -------   --------
    (10m)^2     (d-10m)^2

    And solved for d
     
  5. Jan 20, 2004 #4
    It should be
    [tex]\frac{k*10nC}{r^2}-\frac{k*20nC}{(10+r)^2}=0[/tex]

    coz fields adds upto zero on the position left to origin

    i should say for x=-24
     
    Last edited: Jan 20, 2004
  6. Jan 21, 2004 #5
    thanks!!
     
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