Rotational Mechanics Glossary

Rate of change of angular velocity: alpha = d omega/dt.

Integral of torque over time. Equals change in angular momentum.

L = I omega. Conserved when net external torque is zero.

The angle of rotation measured in radians from a reference direction.

Rate of change of angular position: omega = d theta/dt.

Rotational analog of mass. I = integral r^2 dm. Depends on mass distribution.

I = I_cm + Md^2. Relates I about CM to I about a parallel axis.

Slow rotation of the spin axis of a gyroscope due to external torque.

k where I = Mk^2. Effective distance of mass from axis.

Condition where v_cm = R omega. No relative sliding at contact point.

KE_rot = (1/2) I omega^2. Energy due to spinning motion.

Rotational analog of force. tau = r x F. Causes angular acceleration.