This document discusses momentum and its relationship to mass and velocity. It defines momentum as being directly proportional to mass and velocity, and that it is a measure of an object's resistance to stopping. Greater momentum can be achieved by increasing mass or velocity. Impulse is defined as being equal to force multiplied by time, and that it is equal to the change in momentum of an object. The principle of conservation of momentum is explained, which is that the total momentum of an isolated system remains constant if no external forces act on it.