Linear Momentum Lab Activity
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A closed system is a system which has no external forces acting on it. In other words, if a system is closed, it is not interacting with anything which is located outside of the system.
In the real world, there are no true closed systems, unless you consider the universe to be a closed system. However, in physics we often loosen the definition of a closed system to mean a system with zero total outside force acting on it.
According to the Law of Conservation of Linear Momentum, when a system is closed, the total linear momentum of the system will not change. In other words, if zero total outside force acts on a system, its total momentum will not change.
Let's imagine that the system in consideration is the car and truck in the image below. If zero total outside force acts on the system, then the total linear momentum of the system will remain the same, even after the car and truck collide. Furthermore, if we know (or can calculate) the total linear momentum of the system before the collision, we know that total linear momentum of the system after the collision.
In the real world, there are no true closed systems, unless you consider the universe to be a closed system. However, in physics we often loosen the definition of a closed system to mean a system with zero total outside force acting on it.
According to the Law of Conservation of Linear Momentum, when a system is closed, the total linear momentum of the system will not change. In other words, if zero total outside force acts on a system, its total momentum will not change.
Let's imagine that the system in consideration is the car and truck in the image below. If zero total outside force acts on the system, then the total linear momentum of the system will remain the same, even after the car and truck collide. Furthermore, if we know (or can calculate) the total linear momentum of the system before the collision, we know that total linear momentum of the system after the collision.
The Law of Conservation of Linear Momentum Self-Quiz
Mixed-up sentence exercise
Put the parts in order to form a sentence. When you think your answer is correct, click on "Check" to check your answer. If you get stuck, click on "Hint" to find out the next correct part.