Question

Find dimension of moment of inertia. Is moment of inertia a vector or scalar?

Answer 1

We know that the moment of inertia is given by:

$I=\int dm{R}^2$

So, the dimension of the moment of inertia is:

$I=\left[Mass\right]{\left[Length\right]}^2$

$\left[Mass\right]$=$\left[M\right]$ and $\left[Length\right]=\left[L\right]$

So, $\left[I\right]$$=\left[M\right]{\left[L\right]}^2$

Moment of inertia in rotatory motion is equivalent to mass in translatory motion.

As mass is scalar quantity, it is also a scalar quantity.