A flywheel is a solid disk that rotates about an axis that is perpendicular to t
ID: 2143069 • Letter: A
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 116-mile trip in a typical midsize car produces about 4.41 x 109 J of energy. How fast would a 40.7-kg flywheel with a radius of 0.548 m have to rotate to store this much energy? Give your answer in rev/min.
Explanation / Answer
for disc I = mR^2 /2
= 40.7 * 0.548 *0.5482 /2
= 6.111 kg.m^2
energy = 1/2 I W^2
4.41 x 10^9 = 0.5*6.111 * W^2
W = 37990.47 radians/sec
= 37990.47 *(1/2*pi) rev/sec
= 37990.47 *(1/2*pi)*60 rev/min
=362966.2738 rev/min
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.