A cylinder has inner and outer radii of #9 cm# and #16 cm#, respectively, and a mass of #4 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #10 Hz# to #15 Hz#, by how much does its angular momentum change?

1 Answer
Feb 16, 2017

Answer:

The change in angular momentum is #=2.122.12kgm^2s^(-1)#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

The change in angular momentum is

#Delta L=I*Delta omega#

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

#Delta omega =(15-10)*2pi=(10 pi )rads^-1#

So, #I=4*(0.09^2+0.16^2)/2=0.0674kgm^2#

#L=10pi*0.0674=2.12kgm^2s^(-1)#