Question

What is the moment of inertia of a pendulum with a mass of `7 kg` that is `4 m` from the pivot?

Answer 1

`112kg.m^2`

Explanation:

Assuming this is a simple pendulum, ie the mass and dimensions of the pendulum bob is small compared to its overall dimensions, we may simple approximate its moment of inertia as follows :

`I=MR^2`

`=7xx4^2`

`=112kg.m^2`.

(If however the pendulum is compound, then one would need to use alternative formulae involving centre of mass and precise definitions of `I`).