Momentum is the product of an object's mass and velocity, and it represents how difficult it is to stop or change its motion.
Conservation of Momentum: This principle states that in a closed system, the total momentum before an event is equal to the total momentum after the event, as long as no external forces act on the system.
Collisions: Collisions occur when two objects interact with each other for a short period of time, resulting in changes in their velocities.