System of Particles and Rotational Motion - Revision Notes
CBSE Class XI PHYSICS Revision Notes CHAPTER 7 SYSTEM OF PARTICLES AND ROTATIONAL MOTION Centre of mass Moment of a Force Equilibrium of a rigid body Moment of inertia 1. Ideally, a rigid body is one for which the distances between different particles of the body do not change, even though there are forces on them. 2. A rigid body fixed at one point or along a line can have only rotational motion. A rigid body not fixed in some way can have either pure translation or a combination of translation and rotation. 3. In rotation about a fixed axis, every particle of the rigid body moves in a circle which lies in a plane perpendicular to the axis and has its centre on the axis. Every Point in the rotating rigid body has the same angular velocity at any instant of time. 4. In pure translation, every particle of the body moves with the same velocity at any instant of time. 5. Angular velocity is a vector. Its magnitude is ω = d θ d t ω = d θ d t and it is directed along...