A flywheel of mass 0.2 kg and radius 10 cm is rotating with `5//pi "rev/s"` about an axis perpendicular to its plane passing through its centre. Calculate angular momentum and kinetic energy of flywheel.

Explanation

Angular velocity `omega = 2pi xx (5)/(pi)-10` rad/s
Moment of inertia `I=mr^(2)=(0.2)(0.1)^(2)=2xx10 kg.m^(2)`
Angular momentum `= I omega = 2xx10^(-3)xx10`
`=2xx10^(-2)J-s` or `2xx10^(-2)kg.m^(2)s^(-1)`
Kinetic energy =
`(1)/(2)I omega^(2)=(1)/(2)xx2xx10^(-3)xx(10)^(2)=0.1 J`.