A cylinder has inner and outer radii of #2 cm# and #3 cm#, respectively, and a mass of #1 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #6 Hz# to #12 Hz#, by how much does its angular momentum change?

1 Answer
Feb 18, 2017

The change in angular momentum is #=0.0245kgm^2s^(-1)#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

and #omega# is the angular velocity

The change in angular momentum is

#Delta L=I Delta omega#

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

So, #I=1*(0.02^2+0.03^2)/2=0.00065kgm^2#

#Delta omega =(12-6)*2pi rads^-1#

#Delta L=0.00065*12pi=0.0245kgm^2s^(-1)#