Law of conservation of momentum in a non isolated system.

• Ali Hamaiz
In summary, the law of conservation of momentum is not valid in a non-isolated system. An isolated system refers to a system with no external forces and no mass crossing the boundary. Examples of non-isolated systems include a tennis ball in the air and a gun recoiling. In the case of a gun, conservation of momentum can be applied in the direction of the bullet's flight, but a constant force is needed to keep the gun from dropping to the floor. Therefore, the law of conservation of momentum does not hold in a non-isolated system.
Ali Hamaiz
Is the law of conservation of momentum valid in non isolated system . What is an isolated system? My teacher confuses me that the law is valid in an non isolated system . They even say that when we say about the isolated system (meaning they are present ) we do not consider the air resistance or frictional forces is that true? They give me the example of a gun recoiling , I am confused .

Isolated in this case means no external forces and no mass crossing the boundary. A tennis ball in the air is not an isolated system: it will fall to the ground. A gun also, but if you look in the direction of where it's aiming then the momentum in that direction is conserved.

@BvU what are you talking about the direction?

You need a constant force to keep the gun from dropping to the floor. But to calculate the kickback you can use conservation of momentum in the direction the bullet flies.

BvU said:
You need a constant force to keep the gun from dropping to the floor. But to calculate the kickback you can use conservation of momentum in the direction the bullet flies.
[and make sure that you place the boundaries around the "system" so that both gun and bullet remain inside]

What will be the conclusion , will the law of conservation of momentum hold in an non isolated system .

No. See #2.

1. What is the law of conservation of momentum in a non-isolated system?

The law of conservation of momentum states that the total momentum of a system remains constant in the absence of external forces. In a non-isolated system, external forces such as friction or air resistance may act and change the total momentum of the system.

2. How is momentum conserved in a non-isolated system?

In a non-isolated system, the change in momentum of one object is equal and opposite to the change in momentum of another object. This ensures that the total momentum of the system remains constant.

3. What happens to the momentum of an object in a non-isolated system?

The momentum of an object in a non-isolated system can change if there are external forces acting on it. This change in momentum is equal to the net force acting on the object multiplied by the time interval during which the force acts.

4. Can the law of conservation of momentum be violated in a non-isolated system?

No, the law of conservation of momentum is a fundamental law of physics and cannot be violated. In a non-isolated system, the total momentum may change due to external forces, but the change in momentum of one object will always be equal and opposite to the change in momentum of another object, keeping the total momentum constant.

5. How is the law of conservation of momentum applied in real-life situations?

The law of conservation of momentum is applied in various real-life situations, such as car collisions, ballistics, and rocket propulsion. It helps in understanding and predicting the motion of objects and is an essential principle in the field of mechanics.

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