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Continuous Surface Sources

  1. Jan 28, 2012 #1
    1. The problem statement, all variables and given/known data
    Find the total charge on a circular disc of radius ρ = a if the charge density is given by
    ρs = ρs0 (e^−ρ) sin2 φ C/m2 where ρs0 is a constant.
    Are the two limits of integration from 0 -> a for ρ and 0->2∏ for φ? In the example given in the notes, ρ varies, instead of being a constant value. Does this mean that I cannot integrate ρ in this problem?

    2. Relevant equations

    Q = ∫ρdS

    3. The attempt at a solution

    Q = ∫∫ρs0 (e^−ρ) sin^2 (φ) dφdρ...
    Last edited: Jan 28, 2012
  2. jcsd
  3. Jan 28, 2012 #2


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    With the sin term it looks like there is as much positive as negative?

    Edit, now I see the sin^2

    Your integral looks doable.
  4. Jan 28, 2012 #3


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