Flywheels are large massive wheels (disks) used to store energy. They can be spun up slowly, and then the wheel’s energy can be released quickly to accomplish a task that demands high power. A large flywheel has a 2.4 m diameter and a mass of 300 kg. Its maximum angular velocity is 1500 rpm.
a. The flywheel is spun up at a constant torque of 70 Nm. How long does it take the flywheel to reach top speed?
b. How much energy is stored in the flywheel?
c. After reaching top speed, the flywheel is connected to a machine to which it will deliver energy. Half of the energy stored in the flywheel is delivered in 2.5 sec. What is the average power delivered to the machine?
d. How much torque does the flywheel exert on the machine?
2 answers