Significance of Moment of Inertia

Consider Equations (1) , (4) , (6) as above viz,

These equations are analogous to corresponding equations for a particle in translational motion.

analogous to 'm' ; hence the name Moment of Inertia (M.I). It is the inertia of a rigid body in rotational motion about a fixed axis, i.e., the rigid body cannot change its state of rotational motion about a given axis by itself due to its M.I.

The similarity pointed out above between translational motion of a particle and rotational motion of a rigid body can be extended to any equation for the translational motion to the obtain corresponding rotational motion equations,

The table below lists these similarities.

Note : For a discrete system of particles the where as for a continuous system of particles I =ò dm r²

Index

5.1 Rotational motion of a rigid body about a fixed axis
5.2 Rolling Motion
5.3 Law of Conservation of Angular Momentum

Chapter 6