Kinetic energy and the revolutions

AI Thread Summary
To find the kinetic energy stored in the flywheel, the formula for rotational kinetic energy, KE = 0.5 * I * ω², is used, where I is the moment of inertia and ω is the angular velocity in radians per second. The moment of inertia for a solid disk is calculated as I = 0.5 * m * r², with the flywheel's mass and radius provided. To determine how long the car can run using the energy from the flywheel, the total energy stored is divided by the power output of the motor. Participants in the discussion seek clarification on calculating rotational kinetic energy and converting rotational speed to angular velocity. The conversation emphasizes the importance of understanding these calculations to solve the problem effectively.
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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?
 
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What have you tried so far? How do you calculate rotational KE?
 

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