Question

What is the moment of inertia of a rod with a mass of `3 kg` and length of `4 m` that is spinning around its center?

Answer 1

Moment of inertia of given rod is `4kgm^2`.

Explanation:

As the rod is spinning on its own centre , we are considering the moment of inertia of rod with axis perpendicular to rod at midpoint i.e., `I = (mr^2)//12`
This can be done by calculating the moment of inertia of a system `I= Sigmam_i(r_i)^2`.
Now calculating the moment of inertia of rod with given values we get
`I = [3xx(4)^2]//12=4kgm^2`.