A cylinder has inner and outer radii of #8 cm# and #15 cm#, respectively, and a mass of #3 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #15 Hz# to #12 Hz#, by how much does its angular momentum change?

1 Answer
Jul 20, 2017

Answer:

The angular momentum changes by #=0.82kgm^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=3*(0.08^2+0.15^2)/2=0.04335kgm^2#

The change in angular velocity is

#Delta omega=(15-12)*2pi=6pirads^-1#

The change in angular momentum is

#DeltaL=IDelta omega#

#=0.04335*6pi=0.82kgm^2s^-1#