what is law of conservation of momentum

The law of conservation of momentum is a fundamental principle in physics that states that the total momentum of an isolated system remains constant. This means that within a given problem domain, momentum is neither created nor destroyed, but only changes through the action of forces as described by Newtons laws of motion. Momentum is defined as the product of the mass of an object and its velocity, and it is conserved in all three physical directions at the same time. The law of conservation of momentum is based on Newtons third law of motion, which states that every force has a reciprocating equal and opposite force. This principle is a direct consequence of Newtons third law and applies only to an isolated system of objects, where there is no external impulse acting on the system. In practical terms, the conservation of momentum can be observed in collisions between objects, where the total momentum before the collision is equal to the total momentum after the collision. This law is abundantly confirmed by experiment and can even be mathematically deduced on the reasonable presumption that space is uniform. Therefore, the conservation of momentum is a powerful concept that helps in understanding and analyzing the behavior of objects in motion.