This document provides an overview of momentum and collisions. It discusses linear momentum, impulse, the impulse-momentum theorem, conservation of momentum, and elastic and inelastic collisions. Key points include: - Momentum is defined as mass times velocity. - Impulse is the product of force and time. According to the impulse-momentum theorem, impulse causes a change in momentum. - The total momentum of interacting objects before a collision equals the total momentum after (law of conservation of momentum). - Collisions can be perfectly inelastic (objects stick together), elastic (momentum and kinetic energy conserved), or inelastic (kinetic energy not conserved).