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Why can't i calculate this system of electric potential?

  1. Sep 25, 2005 #1
    Hello everyone, i'm having troubles figuring out why this problem is wrong. In the quark model of fundamental particles, a proton is composed of three quarks: two "up" quarks, each having charge +2e/3, and one "down" quark, having charge -e/3. Suppose that the three quarks are equidistant from one another. Take the distance to be 1.32 10-15 m.

    (a) Calculate the electric potential energy of the system of only the two "up" quarks.
    wrong check mark eV
    (b) Repeat for all three quarks.

    for (a) I used the following i found in the boook:
    The electric potential enegery of a system of fixed point charges is equal to the work that must be done by an external agent to assemble the sytem, bringing each chage in from an infintie distance.

    U = W = q2V = (1/4Pi*Eo)((q1*q2)/r);
    U = (1/4Pi*Eo)(2/3)^2/(1.32e-15m) = 3.03E24 eV which is wrong, what did i mess up? Thanks.
  2. jcsd
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