Class 11 Physics Chapter 6 System of Particles and Rotational Motion – Revision Notes

Quick revision notes for Class 11 Physics Chapter 6 (System of Particles and Rotational Motion). These Class 11 Physics Chapter 6 notes are ideal for quick revision just before exams.

Key Concepts

• Centre of mass: X_cm=Σmx/Σm.
• Torque: τ=r×F.
• Angular momentum: L=Iω; τ=dL/dt.

Moment of Inertia

• Sphere: (2/5)MR²; Cylinder: (1/2)MR²; Rod (centre): (1/12)ML².
• Parallel axis: I=I_cm+Md². Perpendicular axis: I_z=I_x+I_y.

Conservation and Rolling

• Angular momentum conserved when net torque=0.
• Rolling KE=½Mv²+½Iω².

One-Line Summary

Rotational motion is described using torque, angular momentum, and moment of inertia, with angular momentum conserved in the absence of external torque, analogous to linear momentum conservation.

Written by Satish

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