1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    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.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook