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How do you find the direction and magnitude from a nucleus?

  1. Feb 8, 2009 #1
    1. The problem statement, all variables and given/known data

    The nucleus of an atom has a charge of 65 protons.

    (a) What are the direction and magnitude of the electric field at 4.9 x 10^-10 m from the nucleus?

    (b) What are the direction and magnitude of the force exerted on an electron located at this distance?

    2. Relevant equations
    E= KQ/d^2
    K= 9 x 10^9

    3. The attempt at a solution

    (a) (9 x 10^9)(65)/(4.9 x 10^-10)^2
    = 2.44e30 N

    Please help clarify if (a) is correct, and what exactly is (b) asking, if any different from (a)?
  2. jcsd
  3. Feb 8, 2009 #2


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    Homework Helper

    I think you need to understand what the charge of 65 protons is.

    It is not 65 coulombs that are the units of the equation you used.

    Having found the field, then b) is asking you to find the force.
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