A cylinder has inner and outer radii of #2 cm# and #5 cm#, respectively, and a mass of #12 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #6 Hz# to #4 Hz#, by how much does its angular momentum change?

1 Answer
Jun 30, 2017

Answer:

The change in angular momentum is #=0.22kgm^2s^-1#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

The mass, #m=12kg#

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

So, #I=12*((0.02^2+0.05^2))/2=0.0174kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

The change in angular velocity is

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

The change in angular momentum is

#DeltaL=0.0174*4pi=0.22kgm^2s^-1#