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Homework Help: (101)Gamma frequency?

  1. Apr 27, 2008 #1
    [SOLVED] (101)Gamma frequency?

    1. The problem statement, all variables and given/known data
    A gamma particle of energy 4.5 MeV is detected as a product of some nuclear reaction (4.5 MeV is 0.72 pJ). What is the frequency of this gamma radiation?

    2. Relevant equations

    3. The attempt at a solution
    I tried using d=vt because it was the closest formula I could find in my notes that had anything to do with frequency. I assumed v=3x10^8. Of course, the answer was not correct. Could someone point me in the right direction here? I figured out every other problem but this one, and I only have 1 attempt left
  2. jcsd
  3. Apr 27, 2008 #2


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    Hi WPCareyDevil,

    What is a gamma particle? (For example, an alpha particle is a helium nuclei, a beta particle is an electron or positron.) Once you identify what it is, what is the formula for its energy?

    (I'm wondering about your choice of d=vt. Is it because of the v? If so, in this equation v is velocity, not frequency.)
  4. Apr 27, 2008 #3
    Well I have done some research and Gamma particles are elctromagnetic radiation (light emission).. E=mc^2 obviously comes to mind, and I could find the mass of the particle, but how does frequency factor in?

    I used d=vt because of the t (t^-1=frequency). It was a long shot and didnt make sense to me, but it was the closest I could find and every once in a while Ill connect with a shot in the dark on Webassign.
  5. Apr 27, 2008 #4


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    That's right; gamma particles are electromagnetic radiation, and when we speak of their particlelike nature we speak of photons.

    So here you need the expression for the energy of a photon. What do you get?
    Last edited: Apr 28, 2008
  6. Apr 28, 2008 #5
    Ah hah! I googled around and found Planck's constant as well as the formula e=hv where v is the frequency. That was something I didnt learn in class at all. Thanks for the help Alphysicist!!!
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