A solid cylinder of mass `20 kg` rotates about its axis with angular speed `100 s^(-1)`. The radius of the cylinder is `0.25 m`. What is the kinetic energy associated with the rotation of the cylinder ? What is the magnitude of angular momentum of the cylinder about its axis ?

Explanation

Kinetic energy associated with the rotation of the cylinder
`E=(1)/(2)I omega^(2)=(1)/(2)xx(1)/(2) MR^(2)xx omega^(2)`
`=(1)/(4)xx20xx0.25xx0.25xx100xx100`
`=3125 J`
Angular momentum `=I omega`
`=(1)/(2)xx20xx0.25xx0.25xx100`
`=62.5 Js`.