A cylinder has inner and outer radii of #5 cm# and #11 cm#, respectively, and a mass of #5 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #15 Hz# to #8 Hz#, by how much does its angular momentum change?

1 Answer
Mar 19, 2017

Answer:

The change in angular momentum is #=1.61kgm^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=5*((0.05^2+0.11^2))/2=0.0365kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

The change in angular velocity is

#Delta omega=(15-8)*2pi=(14pi)rads^-1#

The change in angular momentum is

#DeltaL=0.0365*14pi=1.61kgm^2s^-1#