Angular Impulse: J = integral(tau * dt) = Delta(L) = I*($omega_f$ - $omega_i$)

Analogous to linear impulse (integral of force = change in momentum).

Instantaneous Axis of Rotation (IAOR): For rolling, the contact point is the IAOR. About the IAOR:

• v_{any}_{point} = omega * (distance from IAOR)
• $v_{cm}$ = omega * R (recovers the rolling constraint)
• $v_{top}$ = omega * 2R = 2*$v_{cm}$

Using the IAOR simplifies many velocity calculations in rolling problems because you treat the motion as pure rotation about the contact point.