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Homework Help: Uniform linear charges and plane charges and mastering physics?

  1. Sep 17, 2005 #1
    uniform linear charges and plane charges and mastering physics??

    I am completely stumped on this mastering physics problem, problem 22.34 (same as out of the university physics volume 3 11th edition book) and I cannot find any examples to compare to in my physics book and I have tried multiple times to come up with some solution but none make sense, I was hoping someone could point me in the right direction or show me how to go about solving it.

    the problem is:

    A long line carrying a uniform linear charge density 50 mu[micro] C/m [So 50*10^-6 ; sorry dont know how to make mu character so just clarifying] runs parallel to and 10.0 cm from the surface of a large, flat plastic sheet that has a uniform surface charge density of -100 mu [micro] C/m^2 on one side.

    Find the location of all points where an alpha particle would feel no force due to this arrangement of charged objects.

    as I said before im completely stumped and I have failed attempts about 5 -6 times and I would appreciate any help given. Thanks in advance
  2. jcsd
  3. Sep 18, 2005 #2


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    An alpha partice would feel no force at those places where the electric field is zero, right?
    So find the electric field. If you know the electric field of a plane sheet and that of a point charge you can just add them up. (Convince yourself that the electric field of the wire/plane doesn't affect the charge distribution on the plane/wire).

    It would also help if you showed what you have done so far.
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