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Homework Help: E of Infinite Thin Plane

  1. Sep 27, 2010 #1
    1. The problem statement, all variables and given/known data
    An infinite plane (2y+z=3) has surface charge density of sigma=2 microC/m2. Find the electric field at (0,0,2)m

    2. Relevant equations

    3. The attempt at a solution
    Would this just be E=sigma/2*epsilon-naught? Would the answer just be 1 microC/m2 over epsilon-naught?
  2. jcsd
  3. Sep 27, 2010 #2
    So that would be the right magnitude, but what about direction?
  4. Sep 28, 2010 #3
    Isn't it just the direction normal to the plane? In this case would it be (0,2,1)?
  5. Sep 28, 2010 #4
    Right, and really you want a unit vector so divide by sqrt(5). Looks good to me.
  6. Sep 28, 2010 #5
    I think both components are supposed to be negative, but either way I got it it now. Thanks.
  7. Sep 28, 2010 #6
    Oh right, well I suppose that, yeah, you will have the negative. I spaced that one out.
  8. Sep 28, 2010 #7
    No problem. Thanks.
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