A cylinder has inner and outer radii of #2 cm# and #16 cm#, respectively, and a mass of #9 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?

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Answer 1 · 2017-02-27T12:46:21

The change in angular momentum is #=3.68kgm^2s^-1#

The angular momentum is #L=Iomega#

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

So, #I=9*(0.02^2+0.16^2)/2=0.117kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

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

#DeltaL=0.117*10pi=3.68kgm^2s^-1#