A cylinder has inner and outer radii of $16 cm$ and $24 cm$ , respectively, and a mass of $4 kg$ . If the cylinder's frequency of rotation about its center changes from $5 Hz$ to $2 Hz$ , by how much does its angular momentum change?

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Answer 1 · 2017-11-01T07:32:15

The change in angular momentum is $=3.14kgm^2s^-1$

The angular momentum is $L=Iomega$

and $omega$ is the angular velocity

The mass of the cylinder is $m=4kg$

The radii of the cylinder are $r_1=0.16m$ and $r_2=0.24m$

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

So, $I=4*((0.16^2+0.24^2))/2=0.1664kgm^2$

The change in angular velocity is

$Delta omega=Deltaf*2pi=(5-2) xx2pi=6pirads^-1$

The change in angular momentum is

$DeltaL=IDelta omega=0.1664 xx6pi=3.14kgm^2s^-1$

A cylinder has inner and outer radii of 16 cm16 cm and 24 cm24 cm, respectively, and a mass of 4 kg4 kg. If the cylinder's frequency of rotation about its center changes from 5 Hz5 Hz to 2 Hz2 Hz, by how much does its angular momentum change?