A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible alternative to batteries in electric cars. The gasoline burned in a 330-mile trip in a typical midsize car produces about 2.00 109 J of energy. How fast would a 10-kg flywheel with a radius of 0.25 m have to rotate to store this much energy? Give your answer in rev/min.

Answer 1

2e9 = 1/2 I ω^2
Have to look up I for a solid disc, solve for ω