Question

What is the angular momentum of a rod with a mass of `15 kg` and length of `7 m` that is spinning around its center at `19 Hz`?

Answer 1

The angular momentum is `=7312.1kgm^2s^-1`

Explanation:

`"Angular momentium" (kgm^2s^-1)="Moment of inertia"(kgm^2)xx"Angular velocity "(rads^-1)`

The angular momentum is `L=Iomega`

where `I` is the moment of inertia

and `omega` the angular velocity

The mass of the rod is `m=15kg`

The length of the rod is `L=7m`

The moment of inertia of a rod, rotating about the center is

`I=1/12*mL^2`

`=1/12*15*7^2= 61.25 kgm^2`

The frequency is `f=19Hz`

The angular velocity is `omega=2pif=2*19*pi=38pirads^-1`

The angular momentum is

`L=Iomega=61.25*38pi=7312.1kgm^2s^-1`