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Homework Help: Uncertainty Principle

  1. Sep 29, 2009 #1
    1. The problem statement, all variables and given/known data
    http://img340.imageshack.us/img340/3249/question.jpg [Broken]

    2. Relevant equations

    3. The attempt at a solution

    Well, I calculated P using a wavelength of .1 femtometer. Then I plugged it into the energy equation. However, I got 1.5e14 eV, while the answer sheet says it's supposed to be 12 GeV. Have I done something wrong wrong? On the answer sheet my professor calculated P, and I got the same answer he got, but after that he just says therefore E=12GeV, not showing how he came to that conclusion.

    Thanks for any help!
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Sep 29, 2009 #2
    You cannot neglect relativistic effects at such high energies, thus the equation
    [tex]E = \frac{p^{2}}{2m}[/tex] does not hold.
    Instead you should use the relativistic equation
    [tex]E^{2} = m_{0}^{2} c^{4} + p^{2} c^{2}[/tex]
  4. Sep 29, 2009 #3
    Ahh that makes sense and gives e the right answer. Thanks!
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