A cylinder has inner and outer radii of $2 cm$ and $12 cm$ , respectively, and a mass of $2 kg$ . If the cylinder's frequency of counterclockwise rotation about its center changes from $15 Hz$ to $12 Hz$ , by how much does its angular momentum change?

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Answer 1 · 2017-06-22T08:32:11

The angular momentum changes by $=0.28kgm^2s^-1$

The angular momentum is $L=Iomega$

The mass, $m=2kg$

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

So, $I=2*((0.02^2+0.12^2))/2=0.0148kgm^2$

The change in angular momentum is

$DeltaL=IDelta omega$

The change in angular velocity is

$Delta omega=(15-12)*2pi=(6pi)rads^-1$

The change in angular momentum is

$DeltaL=0.0148*6pi=0.28kgm^2s^-1$

A cylinder has inner and outer radii of 2 cm2 cm and 12 cm12 cm, respectively, and a mass of 2 kg2 kg. If the cylinder's frequency of counterclockwise rotation about its center changes from 15 Hz15 Hz to 12 Hz12 Hz, by how much does its angular momentum change?