A cylinder has inner and outer radii of 4 cm4cm and 18 cm18cm, respectively, and a mass of 2 kg2kg. If the cylinder's frequency of counterclockwise rotation about its center changes from 15 Hz15Hz to 16 Hz16Hz, by how much does its angular momentum change?

1 Answer
Mar 5, 2017

The change in angular momentum is =0.214kgm^2s^-1=0.214kgm2s1

Explanation:

The angular momentum is L=IomegaL=Iω

where II is the[moment of inertia

For a cylinder, I=m(r_1^2+r_2^2)/2I=mr21+r222

So, I=2*(0.04^2+0.18^2)/2=0.034kgm^2I=20.042+0.1822=0.034kgm2

The change in angular momentum is

DeltaL=IDelta omega

The change in angular velocity is

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

The change in angular momentum is

DeltaL=0.034*2pi=0.214kgm^2s^-1