A cylinder has inner and outer radii of #2 cm# and #12 cm#, respectively, and a mass of #2 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #24 Hz# to #12 Hz#, by how much does its angular momentum change?

1 Answer
May 2, 2017

Answer:

The change in angular momentum is #=1.12kgm^2s^-1#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

Mass, #m=2kg#

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

So, #I=2*((0.02^2+0.12^2))/2=0.0148kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

The change in angular velocity is

#Delta omega=(24-12)*2pi=(24pi)rads^-1#

The change in angular momentum is

#DeltaL=0.0148*24pi=1.12kgm^2s^-1#