Does a lever/fulcrum reaction demonstrate Newton 3rd Law?

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SUMMARY

The discussion centers on the application of Newton's Third Law of Motion in the context of a lever and fulcrum system. Participants clarify that while force pairs are present, the scenario described does not solely demonstrate action-reaction as implied. Newton's Third Law relates to the conservation of momentum, and multiple force interactions must be considered in mechanics. The consensus emphasizes that understanding all three of Newton's laws is essential for solving mechanics problems effectively.

PREREQUISITES
  • Understanding of Newton's Laws of Motion
  • Basic principles of mechanics
  • Knowledge of force pairs and momentum conservation
  • Familiarity with lever systems and fulcrum dynamics
NEXT STEPS
  • Study the implications of Newton's Third Law in various mechanical systems
  • Explore the concept of conservation of momentum in collision scenarios
  • Investigate the role of multiple force interactions in mechanics
  • Review practical applications of levers and fulcrums in engineering
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Physics students, mechanics enthusiasts, and educators looking to deepen their understanding of Newton's laws and their applications in real-world scenarios.

jimmypantspants
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Say a lever is tilted on a fulcrum with an object on the side in contact with the floor, a mass falls onto the other side, causing the object to go flying. Does this demonstrate Action-reaction ? (action on the lever to action on the object)
 
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No. At least not in the way you seem to imply. There are seversl force pairs involved here.
 
Orodruin said:
No. At least not in the way you seem to imply. There are seversl force pairs involved here.
I agree. N3 refers to conservation of momentum. Third law pairs are present in more than one instance here - but, of course, they are to be found everywhere in mechanics.
I already commented in a recent thread on the same topic that N3 is not the only law that needs to be applied in solving Mechanics problems. Newton stated three laws and he would only have produced one if three were not needed.
 

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