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Finding Electric field magnitude of a wire

  1. Aug 29, 2008 #1
    1. The problem statement, all variables and given/known data
    A plastic wire 8.50cm long carries a charge density of +175 nC/m distributed uniformly along its length. it is lying on a horizontal tabletop

    A) find the magnitude and direction of the electric field this wire produces at a point 6.00 cm directly above its midpoint

    2. Relevant equations

    dq= lamdadx dE= kdq/r^2

    3. The attempt at a solution

    The part where i am stuck is what should the limits of integration be? 0.00 cm to 6.00 cm?

    and what should r^2 be? 6.00 cm?
  2. jcsd
  3. Aug 29, 2008 #2


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    Homework Helper

    Note that both r and x are variables; neither are constants. Express one of them in terms of the other before performing the integration. Use pythagoras theorem here. As for limits of integration, it depends on what you choose to vary, either x or r.
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