What principle states that the total momentum of a closed system remains constant?

The principle that states that the total momentum of a closed system remains constant is known as the conservation of momentum. This principle arises from Newton's laws of motion, particularly the law of action and reaction, which asserts that when two bodies interact, the force exerted by one body on another is equal in magnitude and opposite in direction to the force exerted by the second body on the first.

When these forces act over a period of time, the changes they cause in momentum occur simultaneously, ensuring that any increase in momentum of one body is matched by a corresponding decrease in the momentum of another. Therefore, in the absence of external forces, the total momentum before an interaction will equal the total momentum after the interaction, preserving the overall momentum of the system.

In contrast, the other principles mentioned involve different aspects of physics: conservation of kinetic energy is applicable specifically to elastic collisions where kinetic energy is not transformed into other forms of energy; conservation of angular momentum pertains to systems undergoing rotation or circular motion; and conservation of energy covers the total energy where energy can change forms but cannot be created or destroyed. Each of these principles addresses different scenarios in physics, demonstrating the unique nature of momentum conservation in isolated systems.