The diameter of a solid solid disc is 0.5 m and its mass is 16 kg. What torque will increase its angular velocity from zero to 120 rotations/ minute in 8 seconds?

Explanation

Given : diameter =0.5m, Mass `=16 kg`
Formula: Moment of inertia of solid disc
`I=1/2MR^(2)`
`I=1/2 MR^(2)`
`=1/2xx16xx[0.5/2]^(2)`
`=1/2`
Angular velocity,
`omega=(120xx2pi)/60=4pi`
And change in angular momentum
`DeltaL=I omega-0=I omega`
Angular impulse `tauxxt=DeltaL`
`impliestau=(DeltaL0/l=1/8xx1/2xx4pi`
`=(pi)/4Nm`