Support the Monkey! Tell All your Friends and Teachers

Help / FAQ



5.1 Rotational Motion of a rigid body about a fixed axis

A rigid body is defined as a system of particles, the distance between any pair of which remains unaltered. This is an ideal condition, but objects like a metal block or a log of wood under moderate forces and torques approach very close to being 'rigid' bodies.

The rotational motion of a rigid body about a fixed axis can be described by introducing concepts of Moment of Inertia, torque, angular momentum etc.

Consider a rigid body rotating about a fixed axis. Let mi, be the mass of the ith particle, let ri be its^r distance from the axis and let vi be its tangential velocity ^r to radius ri of the circle in which the particle rotates with same angular velocity as that of the body.

The Quantity I is called the moment of Inertia (M.I) of the rigid body about the given axis. It is defined as the sum over the body of mass of each particle multiplied by the square of its ^r distance from the axis of rotation. Its unit is 1 Kg x m2.


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

All Contents Copyright © All rights reserved.
Further Distribution Is Strictly Prohibited.

In Association with