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Homework Help: Kinetic energy in rotating objects.

  1. Oct 13, 2008 #1
    1. A 75-g phonograph album of 30-cm diameter spins at 33.3 rpm. What is its kinetic energy?

    2. 1/2mv2

    3. well i think that kinetic energy is 1/2mv2 so is it like that but instead of v you put in the 33.3 rpm. like 1/2(75)(33.3)2 maybe?
  2. jcsd
  3. Oct 13, 2008 #2
    [tex] K_e = \frac{1}{2}I\omega^2 [/tex]

    You have to use omega as radians per second, mass has to be in kilograms.
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