Given the task definition and input, reply with output. In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

The conservation of this quantity is a consequence of the translational invariance of the Lagrangian, and this quantity is canonically conjugate to position. The kinetic energy of a particle is equal to this quantity squared divided by two times the mass. Impulse is the change in this quantity. Newton's second law states that the time derivative of this quantity is equal to net force. The net value for this quantity in a system, along with the value of kinetic energy, is conserved in an elastic collision. For 10 points, name this vector quantity defined as mass times velocity.

Science