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Homework Help: Frequency of a state function

  1. Sep 29, 2005 #1
    I have this state function that I've gotten to the form:

    [tex]\Psi = A*\exp[iE_1 t/h] + B*\exp[4iE_1 t/h][/tex]

    where A and B are functions of x. I know the energy. The h's are h-bars.

    The state function is suppose to describe a proton and I'm asked to find the frequency.

    My first thought is to somehow combine the terms such that I would have something like

    [tex]\Psi = C*\exp[i\omega t][/tex]

    Where [tex]\omega[/tex] would be the angular frequency.

    I'm having some trouble trying to get it to this form.

    What I want to know is if this is the correct approach.

    Let me know if I need to give any more info. Thanks in advance.
  2. jcsd
  3. Sep 29, 2005 #2
    If it matters, A and B are trig functions, cos(Pi x / L) and sin(2 Pi x / L) respectively, both times sqrt(2/L).
  4. Sep 29, 2005 #3


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    Well, it helps to know the definition. :smile:

    What you need to do is to find a period of your function -- that is, the smallest positive constant H such that Ψ(t) = Ψ(t + H). (For all t) Then, the period is just the reciprocal of that.
  5. Sep 29, 2005 #4
    Thanks! I'll try that.
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