Momentum and Impulse

Linear momentum is a physical quantity that provides another approach to the behaviour of objects in motion. It is a vector quantity obtained by multiplying the mass of an object by its velocity. It therefore has the unit kg m s−1. Its direction is the same as that of the velocity of the object. The word linear is used to distinguish it from the angular momentum of a rotating body, which we shall meet later. The use of the word ‘momentum’ alone implies linear momentum, and that is the convention we shall adopt here.