Flywheels are large, massive wheels used to store energy. Theycan be spun up slo
ID: 1721868 • Letter: F
Question
Flywheels are large, massive wheels used to store energy. Theycan be spun up slowly, then the wheel's energy can be releasedquickly to accomplish a task that demands high power. An industrialflywheel has a 1.5 m diameter and a mass of 250 kg. Itsmaximum angular velocity is 1200 rpm. A motor spins up the flywheel with a constant torque of 50N*m. How long does it take the flywheel to reach top speed? Flywheels are large, massive wheels used to store energy. Theycan be spun up slowly, then the wheel's energy can be releasedquickly to accomplish a task that demands high power. An industrialflywheel has a 1.5 m diameter and a mass of 250 kg. Itsmaximum angular velocity is 1200 rpm. A motor spins up the flywheel with a constant torque of 50N*m. How long does it take the flywheel to reach top speed?Explanation / Answer
Giventhat the mass of wheel is m = 250 kg Diameter of the wheel is d = 1.5m finalangular velocity is 2 = 1200 rpm = 1200*2/60 rad/s = 125.66 rad/s Torqueis = 50 N.m --------------------------------------------------------------------------------------------- The torque is = I* = ( MR2/2) = ( MR2/2) (2 -1)/t = ( MR2/2) (2 -0)/t ( initial angular velocityis zero) t = ( MR2/2) (2 ) / =---------- sec