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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.
    J
    (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.
    s

    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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