Rotational Motion: notes and previous year questions

Free notes for every topic in rotational motion, with the key formulas and real JEE and NEET questions solved step by step.

Centre of MassThe mass-weighted average position: two masses, many particles, solid bodies, holes, curved shapes, and how the centre of mass moves.
Moment of InertiaHow hard a body is to spin up: I = Σmr², rods, rings, discs and spheres, the radius of gyration, rotational kinetic energy and the rolling race.
Parallel and Perpendicular Axis TheoremsTwo shortcuts for a new axis: I = I_cm + Md² for any body, and I_z = I_x + I_y for flat bodies, and how to use them together.
TorqueThe turning effect of a force: τ = rF sin θ, its direction, τ = Iα, pulleys with mass, equilibrium, the torque of gravity, and sliding against tipping.
Angular MomentumThe momentum of turning: L = r × p and L = Iω, τ = dL/dt, conservation when no outside torque acts, energy, joining up, and orbits.
Rolling MotionMoving along and turning at once: v = Rω, the speeds of points on a wheel, rolling energy, racing down slopes, friction, sliding into rolling, and rolling uphill.