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Homework Help: E-field at various points from two large sheets

  1. Feb 26, 2010 #1
    E-field at various points from two "large" sheets

    1.You've hung two very large sheets of plastic facing each other with distance d between them, as shown in the figure . By rubbing them with wool and silk, you've managed to give one sheet a uniform surface charge density n1 = -n_o and the other a uniform surface charge density n2 = 3n_o .



    2. electric field equations



    3. Ok, I know that since both sheets are "large" that their field strength is uniform and independent of distance. Thus, point 1, for example, I would just add the -n_0 and 3n_o since the field vectors for the left plate point to the right for point one and the vectors from the far plate point left... but how do I do this in terms of n_o / epsilon_o? I tried entering a numerical value based on the simple addition I described but its wrong.
     
  2. jcsd
  3. Feb 26, 2010 #2

    ideasrule

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    Re: E-field at various points from two "large" sheets

    I've no idea what "point one" is, nor which plate is on the left and which is on the right. I think you're on the right track, however. Find the electric field produced by each plate and add them vectorially.
     
  4. Feb 26, 2010 #3
    Re: E-field at various points from two "large" sheets

    Sorry. Point 1 is the left of the left (-n_o) sheet, point to is in between the two sheets, and point 3 is to the right of the right sheet (3n_o).
     
  5. Feb 26, 2010 #4
    Re: E-field at various points from two "large" sheets

    27.P48.jpg
     
  6. Feb 26, 2010 #5
    Re: E-field at various points from two "large" sheets

    Nevermind, I got it. The readings this week were typed up wrong so I hadn't read the right sections. It was simple once I had the equation E_plane = n/2ep_o
     
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