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Homework Help: What is the total kinetic energy of the rod?

  1. Apr 30, 2016 #1
    1. The problem statement, all variables and given/known data
    Uniform rod rotates at axel. What is the total kinetic energy of the rod?

    2. Relevant equations
    deltaKrot = 1/2Iw^2
    deltaKtrans = 1/2mv^2

    3. The attempt at a solution
    I believe the rod has both rotational as well as translation energy because the rod is not rotating about its center of mass. I end up getting 1/2ML^2w^2+1/2Mv^2 which is not the answer choices. (The answer is B).

    Attached Files:

  2. jcsd
  3. Apr 30, 2016 #2

    Doc Al

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    Staff: Mentor

    You can view the rod as having both rotational KE about the center of mass and translational KE of the center of mass. Or you can view the rod as in pure rotation about the given axis. Your choice. Either way, the answer will be the same.

    Two points: (1) How did you get that expression for the rotational KE? (2) Realize that ω and v are related. Express everything in terms of ω.
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