Impulse: Impulse is the change in an object's momentum due to a force applied over a period of time. It can be calculated using $\mathbf{J} = \Delta \mathbf{p} = \mathbf{F}\Delta t$.
Conservation of Momentum: A principle stating that the total linear momentum of a closed system remains constant provided no external forces are acting on it.
Elastic Collision: A type of collision where both kinetic energy and linear momentum are conserved.