Question

What is the angular momentum of a rod with a mass of `8 kg` and length of `7 m` that is spinning around its center at `19 Hz`?

Answer 1

`4387.23(kgm^2)/s`

Explanation:

The angular momentum of a rod is given by `L=Iomega`, where `I` is the moment of inertia and `omega` the angular velocity.

Furthermore, `I=1/12ml^2`, where `m` is the mass and `l` the length of the rod.

Also, `omega=2pif`, where `f` is the frequency.

Calculate `I`.

`I=1/12(8)(7)^2`
`color(white)I=3/4(49)`
`I=36.75kgm^2`

Calculate `omega`.

`omega=2pi(19)`
`omega=38pi(rad)/s`

Using these values, multiply:

`L=Iomega`
`L=36.75*38pi`
`L=4387.23(kgm^2)/s`