To drive a typical car at 40 mnh on a level road for one hour requires about 3.2

Question

To drive a typical car at 40 mnh on a level road for one hour requires about 3.2 times 10^7 J of energy. Suppose one tried to store this much energyin a spinning solid cylindrical flywheel which was then coupled to the wheels of the car A large flywheel cannot be spun too fast or it will fracture. If one used a flywheel of radius 0.60 m and mass 400 kg, what angular speed would be required to store 3.2 times 10^7 J? (Incidentally, 2500 rpm is about the maximum feasible rate of revolution with present materials technology for such a flywheel.) 943 rad/s 3620 rad/s 530 rad/s 1800 rad/s 5470 rad/s

Explanation / Answer

rotational energy = 0.5 I w^2

I = MOI = MR^2/2 = 400*(0.6)^2 / 2 =72 Kgm2

energy = 3.2*10^7 = 0.5* (72 )* w^2

w = 942.809041582 rad/s

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

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