A cylinder has inner and outer radii of #4 cm# and #18 cm#, respectively, and a mass of #2 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #15 Hz# to #16 Hz#, by how much does its angular momentum change?

1 Answer
Mar 5, 2017

Answer:

The change in angular momentum is #=0.214kgm^2s^-1#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the[moment of inertia

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

So, #I=2*(0.04^2+0.18^2)/2=0.034kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

The change in angular velocity is

#Delta omega=(16-15)*2pi=2pirads^-1#

The change in angular momentum is

#DeltaL=0.034*2pi=0.214kgm^2s^-1#