A cylinder has inner and outer radii of #4 cm# and #18 cm#, respectively, and a mass of #1 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #15 Hz# to #9 Hz#, by how much does its angular momentum change?

1 Answer
Jul 26, 2017

Answer:

The change in ngular momentum is #=0.64kgm^2s^-1#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

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

So, #I=1*((0.04^2+0.18^2))/2=0.017kgm^2#

The change in angular velocity is

#Delta omega=(15-9)*2pi=12pirads^-1#

The change in angular momentum is

#DeltaL=IDelta omega#

#=0.017*12pi=0.64kgm^2s^-1#