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Homework Help: Rotational energy of nuclear excited states

  1. Apr 10, 2010 #1
    1. The problem statement, all variables and given/known data
    Rotation of a deformed nucleus is predicted to produce nuclear excited states with energies given by E(J)=J(J+1)hbar/2I. The first two excited states of 238 U are Jpi = 2+(0.045MeV) and Kpi=4+(0.148MeV). Show these energies are consistent with rotational excitation stating any assumptions you make

    3. The attempt at a solution
    I is the moment of inertia of the nucleus. I=2/5 MR^2
    For 238U I=2/5 * (92*938.272 +92*0.511 + 146*939.566) * [1.2 * (238)^1/3 ]^2

    But I am getting a value of 4945058.626MeV fm^2 = 4.945...x10^-24 MeV
    which is not giving me 0.045MeV for the 2+ state!??!?!!

    any idea where I am going wrong?
  2. jcsd
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