A cylinder has inner and outer radii of 9 cm9cm and 16 cm16cm, respectively, and a mass of 4 kg4kg. If the cylinder's frequency of counterclockwise rotation about its center changes from 23 Hz23Hz to 15 Hz15Hz, by how much does its angular momentum change?

1 Answer
Feb 13, 2017

The change in angular momentum is =3.39kgm^2s^(-1)=3.39kgm2s1

Explanation:

The angular momentum is L=IomegaL=Iω

where II is the moment of inertia

The change in angular momentum is

DeltaL=IDelta omega

For a cylinder, I=m(r_1^2+r_2^2)/2

So, I=4*(0.09^2+0.16^2)/2=0.0674kgm^2

Delta omega=(23-15)*2pi=16pirads^-1

DeltaL=0.0674*16pi=3.39kgm^2s^(-1)