A cylinder has inner and outer radii of 8 cm and 16 cm, respectively, and a mass of 6 kg. If the cylinder's frequency of counterclockwise rotation about its center changes from 9 Hz to 3 Hz, by how much does its angular momentum change?

1 Answer
Jun 9, 2017

The change in angular momentum is =3.62kgm^2s^-1

Explanation:

The angular momentum is L=Iomega

where I is the moment of inertia

Mass, m=6kg

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

So, I=6*((0.08^2+0.16^2))/2=0.096kgm^2

The change in angular momentum is

DeltaL=IDelta omega

The change in angular velocity is

Delta omega=(9-3)*2pi=(12pi)rads^-1

The change in angular momentum is

DeltaL=0.096*12pi=3.62kgm^2s^-1