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Homework Help: Λ(Κ) for electron

  1. Apr 5, 2006 #1
    1)How can I find the wavelength as a function of the kinetic energy i)for photons, ii)for electrons?

    i)For photons.
    I think that I found it. I used the relation: E^2=c^2*p^2+(mc^2)^2
    The photon's rest mass is 0. So we get: E=c*p
    p=E/c ---> p=h*v/c --->p=h/λ
    Finally: λ=c*h/E

    ii)For electrons.
    I don't know what to do. Do I have to use the same equations?
  2. jcsd
  3. Apr 5, 2006 #2

    Meir Achuz

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    For the electron use pc=\sqrt{E^2-m^2c^4}, and then substiltute
    T=KE=E-mc^2, so E=T+mc^2.
  4. Apr 5, 2006 #3
    I assume K is the kinetic energy, but what's T???:confused:
  5. Apr 5, 2006 #4
    KE=kinetic energy, T is standard notation for it too.
  6. Apr 5, 2006 #5
    Never mind, got it :rofl:
  7. Apr 5, 2006 #6
    Thanks INHA.
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