A cylinder has inner and outer radii of #4 cm# and #7 cm#, respectively, and a mass of #6 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #7 Hz# to #12 Hz#, by how much does its angular momentum change?

1 Answer
Apr 15, 2017

Answer:

The change in angular momentum is #=0.61kgm^2s^-1#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

Mass, #m=1kg#

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

So, #I=6*((0.04^2+0.07^2))/2=0.0195kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

The change in angular velocity is

#Delta omega=(12-7)*2pi=(10pi)rads^-1#

The change in angular momentum is

#DeltaL=0.0195*10pi=0.61kgm^2s^-1#