A cylinder has inner and outer radii of #2 cm# and #5 cm#, respectively, and a mass of #8 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #6 Hz# to #8 Hz#, by how much does its angular momentum change?

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Answer 1 · 2017-02-26T09:26:42

The change in angular momentum is #=0.15kgm^2s^-1#

The angular momentum is #L=Iomega#

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

So, #I=8*(0.02^2+0.05^2)/2=0.0116kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

#Delta omega=(8-6)*2pi=4pirads^-1#

#DeltaL=0.0116*4pi=0.15kgm^2s^-1#