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Homework Help: What is the potential difference VA-VB?

  1. Feb 20, 2006 #1
    Points A (3 m, 2 m) and B (6 m, 6 m) are in a
    region where the electric field is uniform and
    given by E = Exi + Eyj, where Ex = 3 N/C
    and Ey = 2 N/C.
    What is the potential difference VA-VB?
    Answer in units of V.

    I used E(rB-rA)

    sqr rt(13) times (sqr rt (72) - sqr rt (13)) = 17.59

    this is wrong. What am i doing wrong?
     
  2. jcsd
  3. Feb 20, 2006 #2
    Given the field do you know how to calculate the potential (difference) in terms of a line intergral?
     
  4. Feb 21, 2006 #3
    help within the hour is much appreciated... I'm thinking maybe it should be negative?
     
  5. Feb 21, 2006 #4

    nrqed

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    Science Advisor
    Homework Helper
    Gold Member

    For a uniform E field, the potential difference is given by a scalar product (NOT a product of magnitudes!), [tex] \Delta V = - \vec E \cdot \vec r[/tex]

    Pat
     
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