Understanding Conservation of Momentum in Two-Cart Collision

Understanding Conservation of Momentum

When cart A, moving with an initial velocity +v, hits cart B, which is at rest, and then cart A stops while cart B moves off with the same velocity, we are observing a classic physics problem dealing with conservation of momentum. In this scenario, assuming there is no external force acting on the system and that the carts have equal mass, the system is closed and isolated. Therefore, the total momentum of the system is conserved. The velocity of the center of mass of the carts before and after the collision remains constant because the system’s total momentum remains unchanged.

During the collision, cart A transfers its momentum to cart B. Since the carts have equal mass and there is no net external force, cart B must move with the velocity that cart A had initially in order to conserve momentum. Consequently, the center of mass of the system has not changed its velocity because of this momentum exchange. The phenomenon observed can be described by the principle of conservation of momentum in physics, which states that when no external forces act on a system, the total momentum remains constant in both magnitude and direction.