A cylinder has inner and outer radii of #16 cm# and #24 cm#, respectively, and a mass of #3 kg#. If the cylinder's frequency of rotation about its center changes from #2 Hz# to #7 Hz#, by how much does its angular momentum change?

1 Answer
Jun 20, 2017

Answer:

The angular momentum changes by #=3.92kgm^2s^-1#

Explanation:

The angular momentum is #L=Iomega#

where #I# is the moment of inertia

The mass, #m=3kg#

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

So, #I=3*((0.16^2+0.24^2))/2=0.1248kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

The change in angular velocity is

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

The change in angular momentum is

#DeltaL=0.1248*10pi=3.92kgm^2s^-1#