A flywheel in the form of a disc is initially at rest. When a constant torque acts on it for one minute, it attains a speed of 600 rpm. Calculate the torque, if mass and radius of the disc are 10 kg and 0.4m respectively.

A flywheel in the form of a disc is initially at rest. When a constant

1.	A flywheel in the form of a disc is initially at rest. When a constant torque acts on it for one minute, it attains a speed of 600 rpm. Calculate the torque, if mass and radius of the disc are 10 kg and 0.4m respectively.
Answer» SOLUTION :M = 10kg, R=0.4m `I=(MR^(2))/(2)=10((0.4)^(2))/(2)0.8kgm^(2)` `omega_(i)=0,omega_(f)=(2piN)/(t)=(2pi(600))/(60)=20pirads^(-1)` TIME taken for the change of speed,t=60 s. `alpha=(omega_(f)-omega_(i))/(t)=(20pi-0)/(60)=(pi)/(3)rads^(-1)` The torque, `tau=Ialpha=0.8((pi)/(3))=0.8379Nm`.