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Homework Help: Energy of electron

  1. Aug 9, 2007 #1
    So I'm staring at this equation in my book and im not sure what the variable k represents in this equation: E=(p[tex]^{2}[/tex]/2m)-(ke[tex]^{2}[/tex]/r) and im assuming e refers to the charge of the electron.
  2. jcsd
  3. Aug 9, 2007 #2

    k=1/4pi epsilon0
  4. Aug 9, 2007 #3


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    "K" is the constant in Coloumb's Law, just like "G" is a constant in Newton's Law of Gravity.

    Numerically, K has a value around 9X10^9 Nm^2/C^2.

    As mentioned above by patapat, K can also be represented as:

    [tex]K=\frac{1}{4\pi\epsilon_0}[/tex] where [tex]\epsilon_0[/tex]= 8.85X10^-12 and is called the permittivity of free space, which is a fundamental constant of electromagnetism.
  5. Aug 11, 2007 #4
    some of the books use 'k' for representing the quantity '1/4pi*e0'
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