A cylinder has inner and outer radii of 2 cm2cm and 12 cm12cm, respectively, and a mass of 2 kg2kg. If the cylinder's frequency of counterclockwise rotation about its center changes from 24 Hz24Hz to 18 Hz18Hz, by how much does its angular momentum change?

1 Answer
Jan 29, 2017

The answer is =0.558 kg ms^-1=0.558kgms1

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=2*(0.02^2+0.12^2)/2=0.0148kgm^2

Delta omega=(24-18)*2pi =12pi rads^-1

DeltaL=0.0148*12pi=0.558kgms^(-1)