The discussion centers on the principle of conservation of momentum in the context of a car coming to a stop. It is established that momentum is not conserved during this process due to the presence of external forces, such as friction from the road and braking forces. Before stopping, the car has a non-zero momentum, which becomes zero after stopping. However, when considering the entire car-earth system, momentum is conserved overall, as the forces acting on the car are external to the car itself.
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And if you consider the entire car-earth system?Mohammed Shoaib said:Momentum is conserved when no external force acts on the system. When the car comes to normal stop, the external force from the road or from the brake acts on the car to stop. Hence, the conservation of principle is not valid in this process. Am I right.
Yes, it should be. Yet the car momentum after is zero and the one before non zero.Mohammed Shoaib said:Then momentum is conserved. Is it not?
Thanks for your kind help.Orodruin said:Yes, it should be. Yet the car momentum after is zero and the one before non zero.
This is a conundrum for many people who are just learning conservation of momentum.