ANGULAR MOMENTUM!

L = r × p  or  L = Iω


2nd Law for Torques: ∑τext = dL/dt.



If no external torques act, the total angular momentum L of a system is conserved.  If rotation about a vertical axis is the only possible rotation, for part of the system, then that component of the total angular momentum is conserved.

PRECESSION!





ROTATIONAL STABILITY!



Maximum rotational inertia axis

Minimum rotational inertia axis

Intermediate rotational inertia axis

Next!