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Compton effect question.

  1. Jan 26, 2013 #1
    1. The problem statement, all variables and given/known data

    If x ray with a weavelength of 4.5*10^-12m are used in a Compton effect experiment and are scattered at an anlge of 53.0 degree, the wavelength of the scattered radiation is?

    ANS: 5.47*10^-12

    2. Relevant equations



    3. The attempt at a solution

    The only thing i could think of was Δλ=h/mc*(1-cosθ)
    which doesnt work seeing as how the xray didnt impact anything, i even tried it as if it impaced an electron using the mass of the electron. What formula or concept am i missing?
     
  2. jcsd
  3. Jan 26, 2013 #2

    SammyS

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    In Compton scattering, the x-rays are usually scattered by electrons.

    With that, I get the given answer.
     
    Last edited: Jan 26, 2013
  4. Jan 26, 2013 #3

    rude man

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    For m did you use the rest mass of the electron? 'Cause the formula is correct.
     
  5. Jan 26, 2013 #4
    I did

    6.63*10^-34/ 9.11*10^31 * 3*10^8 * (1-cos53)= 9.65959164*10^-13

    Then ANS - 4.5*10^-12 which yields 3.53*10^-12.

    what did i do wrong?
     
  6. Jan 26, 2013 #5

    SammyS

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    How about ANS + 4.5*10^-12 ?
     
  7. Jan 26, 2013 #6
    oh, how come its plus isnt Δλ= λi-λf, or is it plus? isnt the change in something usually subtract?
     
  8. Jan 26, 2013 #7

    SammyS

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    You start with λi and finish with λf , so λi + Δλ = λf . In other words, Δλ = λf - λi , like with anything else.
     
  9. Jan 26, 2013 #8
    ah.. silly mistakes are the ones that always get you thank you
     
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