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Conservation of Energy/momentum in Photoelectric process

  1. Sep 1, 2011 #1
    1. The problem statement, all variables and given/known data

    Show that a free electron cannot absorb a photon and conserve both energy and momentum in the process. Hence, the photoelectric process requires a bound electron. (Eisberg and Resnick 2nd Ed)

    2. Relevant equations

    hv = E
    p = K / c
    E2 = (pc)2 + (m0c2)2

    3. The attempt at a solution

    I've simply shown since
    E2 = (pc)2 + (m0c2)2,

    rest energy of a moving electron isn't zero and thus energy and momentum cannot be conserved. Is this argument true/suffice?
     
    Last edited: Sep 1, 2011
  2. jcsd
  3. Sep 1, 2011 #2

    vela

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    I don't see how the conclusion follows from the premise, and I suspect you don't either since you asked if the argument was true.
     
  4. Sep 1, 2011 #3
    How/where then should I start?
     
  5. Sep 2, 2011 #4

    vela

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    Start by writing the equations for the conservation of energy and momentum the electron and photon would have to satisfy.
     
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