In the top row labeled Before Collision, two train cars approach one another with a grey arrow pointing to each car. The left car has below it m subscript 1 = 600 kilograms v subscript 1 = 4 meters per second. The right car has below it m subscript 2 = 400 kilograms v subscript 2 = -2 meters per second. In the bottom row labeled After Collision, two train cars move away from one another with a grey arrow pointing away from each car. a
Consider a system to be two train cars traveling toward each other.
What is the total momentum of the system before the train cars collide?
kg • m/s
What must the total momentum of the system be after the train cars collide?
kg • m/s
The total momentum of the system before the train cars collide can be calculated as follows:
Total momentum before collision = (m1 * v1) + (m2 * v2)
= (600 kg * 4 m/s) + (400 kg * -2 m/s)
= (2400 kg*m/s) + (-800 kg*m/s)
= 1600 kg*m/s
Therefore, the total momentum of the system before collision is 1600 kg*m/s.
According to the law of conservation of momentum, the total momentum of the system after the train cars collide must also be 1600 kg*m/s.