A flywheel is a solid disk that rotates about an axis that is perpendicular to t

Question

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 301-mile trip in a typical midsize car produces about 1.24 x 109 J of energy. How fast would a 12.0-kg flywheel with a radius of 0.493 m have to rotate to store this much energy? Give your answer in rev/min.

Explanation / Answer

Moment of Inertia of the flywheel, I = ½m*r² = 0.5*12.0*0.493^2 = 1.46 kgm²

E = ½Iw²

=> w = [2E/I] = [2*1.24x10^9/1.46]

w = 41239 rad/sec

convert this in revolution / min

rpm = w*[60/2] = (41239*60) / (2*3.141) = 393873

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.