Rotational motion extends Newton's laws from point particles to rigid bodies. The key quantity is moment of inertia (I = sum(m_i * r_i^2)), which depends on both mass distribution and axis of rotation. Standard results: rod about centre ML^2/12, disc MR^2/2, solid sphere (2/5)MR^2, ring MR^2.

The parallel axis theorem (I = I_cm + Md^2) shifts axes; the perpendicular axis theorem (I_z = I_x + I_y) applies to 2D bodies only. Torque (tau = r x F) is the rotational analogue of force, obeying tau = Ialpha. Angular momentum (L = Iomega) is conserved when external torque is zero.

Rolling without slipping combines translation and rotation: v_cm = Romega. Total KE = (1/2)Mv^2(1 + k^2/R^2). On an incline, acceleration a = gsin(theta)/(1 + k^2/R^2), making the solid sphere fastest and ring slowest.

Key problem-solving approach: identify axis, compute MOI, apply tau = I*alpha or energy conservation, and use rolling constraints.