A cylinder has inner and outer radii of #8 cm# and #18 cm#, respectively, and a mass of #1 kg#. If the cylinder's frequency of counterclockwise rotation about its center changes from #15 Hz# to #9 Hz#, by how much does its angular momentum change?

1 Answer
May 31, 2017

Answer:

The change in angular momentum is #=1.46kgm^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=1*((0.08^2+0.18^2))/2=0.0388kgm^2#

The change in angular momentum is

#DeltaL=IDelta omega#

The change in angular velocity is

#Delta omega=(15-9)*2pi=(12pi)rads^-1#

The change in angular momentum is

#DeltaL=0.0388*12pi=1.46kgm^2s^-1#