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

1 Answer
May 2, 2017

The change in angular momentum is =1.12kgm^2s^-1

Explanation:

The angular momentum is L=Iomega

where I is the moment of inertia

Mass, m=2kg

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

The change in angular momentum is

DeltaL=IDelta omega

The change in angular velocity is

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

The change in angular momentum is

DeltaL=0.0148*24pi=1.12kgm^2s^-1