A car traveling 25 m/s to the north collides with a car traveling 15 m/s to the south. Each car has a mass of 1100 kg. If the system is defined as the two cars, what is the change in momentum of the system due to the collision?
If the system is defined as the two cars before the collision, during the collision, and after the collision, there is no change in total momentum (law of conservation of momentum).