Law of conservation of momentum in a non isolated system.

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SUMMARY

The law of conservation of momentum is not valid in a non-isolated system when external forces are present. An isolated system is defined as one where no external forces act and no mass crosses its boundaries. In the context of a gun recoiling, while the momentum of the bullet and gun system is conserved in the direction of the bullet's motion, the overall system is not isolated due to gravitational forces acting on the gun. Therefore, the law of conservation of momentum does not apply universally in non-isolated systems.

PREREQUISITES
  • Understanding of isolated vs. non-isolated systems
  • Basic principles of momentum in physics
  • Knowledge of external forces such as gravity and friction
  • Familiarity with conservation laws in physics
NEXT STEPS
  • Research the implications of external forces on momentum conservation
  • Study examples of isolated systems in classical mechanics
  • Explore the concept of momentum in various physical scenarios, such as collisions
  • Learn about the role of friction and air resistance in momentum calculations
USEFUL FOR

Students of physics, educators explaining momentum concepts, and anyone interested in the applications of conservation laws in real-world scenarios.

Ali Hamaiz
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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 .
 
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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.
 

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