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Homework Help: Kinetic energy and the revolutions

  1. Nov 17, 2007 #1
    A car is designed to get its energy from a rotating flywheel with a radius of 1.90 m and a mass of 510.0 kg. Before a trip, the disk-shaped flywheel is attached to an electric motor, which brings the flywheel's rotational speed up to 1008.0 rev/min.

    (a) Find the kinetic energy stored in the flywheel.
    (b) If the flywheel is to supply as much energy to the car as a 7457 W motor would, find the length of time the car can run before the flywheel has to be brought back up to speed again.

    trying to solve this problem is killing me.. Any hints or tips?
  2. jcsd
  3. Nov 17, 2007 #2

    Doc Al

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    Staff: Mentor

    What have you tried so far? How do you calculate rotational KE?
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