A cylinder has inner and outer radii of #8 cm# and #12 cm#, respectively, and a mass of #8 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #1 Hz# to #7 Hz#, by how much does its angular momentum change?

1 Answer
Jul 25, 2017

Answer:

The change in angular momentum is #=3.14kgm^2s^-1#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

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

So, #I=8*(0.08^2+0.12^2)/2=0.0832kgm^2#

The change in angular velocity is

#Delta omega=(7-1)*2pi=12pirads^-1#

The change in angular momentum is

#DeltaL=IDelta omega#

#=0.0832*12pi=3.14kgm^2s^-1#