A cylinder has inner and outer radii of #2 cm# and #3 cm#, respectively, and a mass of #1 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #10 Hz# to #12 Hz#, by how much does its angular momentum change?

1 Answer
Jun 19, 2017

Answer:

The change in angular momentum is #=0.0082kgm^2s^-1#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

The mass, #m=1kg#

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

So, #I=1*((0.02^2+0.03^2))/2=0.00065kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

The change in angular velocity is

#Delta omega=(12-10)*2pi=(4pi)rads^-1#

The change in angular momentum is

#DeltaL=0.00065*4pi=0.0082kgm^2s^-1#