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Moment of Inertia of dysprosium-160

  1. Apr 4, 2016 #1
    1. The problem statement, all variables and given/known data
    The nucleus dysprosium-160 (containing 160 nucleons) acts like a spinning object with quantized angular momentum, L2 = l(l + 1) * h_bar2, and for this nucleus it turns out that l must be an even integer (0, 2, 4...). When a Dy-160 nucleus drops from the l = 2 state to the l = 0 state, it emits an 87 keV photon (87 ✕ 103 eV).

    h_bar = reduced planck's constant
    2. Relevant equations

    Kinetic Energy = L2 / 2I , where I is the moment of inertia

    3. The attempt at a solution

    Change in KE = Change in L2 / 2I = 5h_bar2 / 2I
    Substituting and solving for I gave me around 2*10-54 which apparently isn't the answer.
    Am I using the wrong formula?

    edit: rookie mistake, Change in KE = 6 * h_bar.... not 5.
    Last edited: Apr 5, 2016
  2. jcsd
  3. Apr 5, 2016 #2

    Simon Bridge

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    Show your reasoning. Where does the energy come from? Where does it go?
    How did you account for the energy of the photon, for instance?
    Check other sources of mistakes - like the value of I and the units.
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