A cylinder has inner and outer radii of #9 cm# and #16 cm#, respectively, and a mass of #6 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #9 Hz# to #3 Hz#, by how much does its angular momentum change?

1 Answer
Jun 14, 2017

Answer:

The change in angular momentum is #=3.81kgm^2s^-1#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

Mass, #m=6kg#

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

So, #I=6*((0.09^2+0.16^2))/2=0.1011kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

The change in angular velocity is

#Delta omega=(9-3)*2pi=(12pi)rads^-1#

The change in angular momentum is

#DeltaL=0.1011*12pi=3.81kgm^2s^-1#