A cylinder has inner and outer radii of #8 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 #1 Hz#, by how much does its angular momentum change?

1 Answer
Aug 3, 2017

Answer:

The change in angular momentum is #=4.83kgm^2s^-1#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

The mass of the cylinder is #m=6kg#

The radii of the cylinder are #r_1=0.08m# and #r_2=0.16m#

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

So, #I=6*(0.08^2+0.16^2)/2=0.096kgm^2#

The change in angular velocity is

#Delta omega=Deltaf*2pi=(9-1)*2pi=16pirads^-1#

The change in angular momentum is

#DeltaL=I Delta omega=0.096*16pi=4.83kgm^2s^-1#