This concept module on momentum is one of thirteen modules that provide a flexible, laboratory-based physics instructional package designed to meet the specialized needs of students in two-year, postsecondary technical schools. Each of the thirteen concept modules discusses a single physics concept and how it is applied to each energy system. This module explains the mathematical relationships involved with both linear and angular momentum. Elastic and inelastic collisions are considered, as well as the law of conservation of momentum. Included with the concept module are five application modules that discuss a specific application of a single concept in a single energy system, and contain a student laboratory exercise. Laboratory modules included are Angular Momentum of a Flywheel, Impulse and Momentum, Conservation of Momentum in Collisions, Gyroscopes, and Rocket Engines. (LRA)