A cylinder has inner and outer radii of #2 cm# and #16 cm#, respectively, and a mass of #1 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #10 Hz# to #15 Hz#, by how much does its angular momentum change?

1 Answer
Feb 2, 2017

The answer is #=0.41kgms^(-1)#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

The change in angular momentum is

#DeltaL=IDelta omega#

#Delta omega# is the change in angular velocity

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

So, #I=1*((0.02)^2+0.16^2)/2=0.013kgm^2#

#Delta omega=(15-10)*2pi=10pirads^-1#

#DeltaL=0.013*10pi=0.41kgms^(-1)#