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 493-mile trip in a typical midsize car produces about 2.69 x 109 J of energy. How fast would a 29.1-kg flywheel with a radius of 0.332 m have to rotate to store this much energy? Give your answer in rev/min.

Explanation / Answer

Given That

m = 29.1 kg

r = 0.332 m

k = 2.69*10^9 J

I = (1/2)*m*r^2

= 0.5 * 29.1 * (0.332)^2

= 1.6037 kgm^2

k = (0.5)*I*w^2

w = sqrt( k / ((0.5)*I) )

w = sqrt( 2.69*10^9 / (0.5*1.6037) )

w = 57920 rad/s

w = 553095.26 rev/min

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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