A cylinder has inner and outer radii of $8 cm$ and $12 cm$ , respectively, and a mass of $8 kg$ . If the cylinder's frequency of rotation about its center changes from $1 Hz$ to $5 Hz$ , by how much does its angular momentum change?

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Answer 1 · 2017-12-16T16:27:05

The change in angular momentum is $=2.09kgm^2s^-1$

The angular momentum is $L=Iomega$

and $omega$ is the angular velocity

The mass of the cylinder is $m=8kg$

The radii of the cylinder are $r_1=0.08m$ and $r_2=0.12m$

For the cylinder, the moment of inertia is $I=m((r_1^2+r_2^2))/2$

So, $I=8*((0.08^2+0.12^2))/2=0.08322kgm^2$

The change in angular velocity is

$Delta omega=Deltaf*2pi=(5-1) xx2pi=8pirads^-1$

The change in angular momentum is

$DeltaL=IDelta omega=0.0832 xx8pi=2.09kgm^2s^-1$

A cylinder has inner and outer radii of 8 cm8 cm and 12 cm12 cm, respectively, and a mass of 8 kg8 kg. If the cylinder's frequency of rotation about its center changes from 1 Hz1 Hz to 5 Hz5 Hz, by how much does its angular momentum change?