Having developed most of the concepts of rotational motion, there remains but one major concept present in in linear motion, that we have not developed with regards to rotation: momentum. Rotational motion involves a distinct type of momentum. This concept of angular momentum allows further explanation of angular phenomena, and leads to our third great conservation law.
In this SparkNote we will begin by defining angular momentum, both for single particles and for rigid bodies, and then examining the relation between torque and angular momentum. Once this relation has been formulated, we gain the ability to derive the conservation of linear momentum, and apply it to numerous examples of angular motion.
With this SparkNote we complete our study of the mechanics of rotational motion. Just as importantly, with our knowledge of the mechanics of linear and rotational motion, we can explain most of the motion in our universe. From here, we need simply to examine special cases of motion.