# Question #e7044

Sep 12, 2017

Moment means moment of inertia.. See.

#### Explanation:

For smaller objects we suppose them as a particle.But when it is a case of a body of a larger size we cannot make out the body as a particle. We have to calculate the moment of inertia of the object.

Here the large object's part are taken as ${m}_{1} , {m}_{2} , {m}_{3} , {m}_{4}$.
It is formula that moment of inertia of the mass is $m {r}^{2}$ when $m$ is the mass and the $r$ is the distance from the turning axis.
The total moment of inertia of the object is
${m}_{1} {r}_{1}^{2} + {m}_{2} {r}_{2}^{2} + {m}_{3} {r}_{3}^{2} + \ldots = \sum m {r}^{2}$
The moment of the object is written as $I = \sum M {R}^{2}$ or. $\int {r}^{2} \mathrm{dm}$