What is the total momentum in a closed system before and after a collision?

In a closed system, the principle of conservation of momentum states that the total momentum before a collision is equal to the total momentum after the collision. This principle holds true regardless of the type of collision, whether it be elastic or inelastic, as long as no external forces are acting on the system.

Momentum is a vector quantity, calculated by multiplying an object's mass by its velocity. During a collision, the individual momenta of the colliding objects may change as they interact; however, the total momentum across the entire system remains constant. This is because the forces that the objects exert on each other are internal forces, leading to an overall balance that preserves total momentum.

Therefore, the total momentum before the collision equates to the total momentum after the collision, reinforcing the concept that momentum is conserved in a closed system.