The angular momentum of the system changes, as described by $\tau = \frac{dL}{dt}$.

Its speed increases to conserve angular momentum.

Their moment of inertia decreases, and their angular speed increases to conserve angular momentum.

The block and bullet system gains momentum, and the system begins to swing upwards.

The angular velocity must increase to conserve angular momentum, assuming no external torque.

$L = r \times p = r m v \sin(\theta)$

$L = I \omega$

The total angular momentum of a system remains constant unless acted upon by a net external torque.

$\tau = \frac{dL}{dt}$

A measure of an object's resistance to changes in its rotation.

A rotational force that causes a change in angular momentum.

Linear Momentum: $p=mv$, translational motion | Angular Momentum: $L=I\omega$, rotational motion

Elastic: Kinetic energy is conserved, Angular momentum is conserved | Inelastic: Kinetic energy is not conserved, Angular momentum is conserved