In the scenario of a clay ball colliding with a wall, momentum is not conserved due to the presence of external forces and the non-rigid nature of the clay. The Law of Conservation of Momentum applies only when no external forces act on the system and when the bodies involved are rigid. In this case, the clay deforms upon impact, absorbing the reaction force, which alters the momentum of the system. Therefore, while total energy is conserved, the total momentum is not, particularly when considering the interaction with the Earth and the wall.
PREREQUISITESPhysics students, educators, and anyone interested in understanding the principles of momentum conservation in collision events.
paragchitnis said:I think, Law of conservation of momentum is only applied when
1. There is no external force acting on the bodies
2. The bodies in the system are rigid
The clay ball is not rigid and stick to wall. Here total energy of the system is conserved but the total momentum is not.
paragchitnis said:Here we are considering a system of two bodies i.e. a wall and the clay ball. If we consider the motion of the earth, the system will be changed. Momentum will be conserved only if there is no external force acting on the system. The force may be small or large, tangentially or normally, if it is acting on the system the momentum will not conserved.
In the proof of the Law of conservation of momentum we take (For the system of two bodies)
Action force = -(Reaction force)
If any third external force acts on the system, the magnitude and the direction of the action as well as reaction force changes (Depending on the magnitude and direction of external force)
The change in force tends to change in velocity and momentum of the bodies. This force does not change the initial momentum of the system but changes final momentum. Thus the momentum is not conserved.