A cylinder has inner and outer radii of $16 cm$ and $21 cm$ , respectively, and a mass of $3 kg$ . If the cylinder's frequency of rotation about its center changes from $2 Hz$ to $9 Hz$ , by how much does its angular momentum change?

Question

1550 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-10-22T05:52:33

The change in angular momentum is $=4.6kgm^2s^-1$

The angular momentum is $L=Iomega$

and $omega$ is the angular velocity

The mass of the cylinder is $m=3kg$

The radii of the cylinder are $r_1=0.16m$ and $r_2=0.21m$

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

So, $I=3*(0.16^2+0.21^2)/2=0.10455kgm^2$

The change in angular velocity is

$Delta omega=Deltaf*2pi=(9-2)*2pi=14pirads^-1$

The change in angular momentum is

$DeltaL=I Delta omega=0.10455*14pi=4.6kgm^2s^-1$

A cylinder has inner and outer radii of 16 cm16 cm and 21 cm21 cm, respectively, and a mass of 3 kg3 kg. If the cylinder's frequency of rotation about its center changes from 2 Hz2 Hz to 9 Hz9 Hz, by how much does its angular momentum change?