I Does Lagrangian Mechanics Handle Variable Mass System?

AI Thread Summary
Lagrangian mechanics can address variable mass systems, unlike Newtonian mechanics, which struggles due to the changing nature of the object's mass. The discussion highlights the challenges in defining an object with variable mass, particularly in relation to Newton's laws, which apply to constant mass systems. Critics argue that without a fixed mass, it becomes complex to formulate the second law of motion. The conversation also points out that many online sources misinterpret the treatment of variable mass systems, emphasizing the importance of accurate information. Understanding these principles is crucial for applications like rocketry, where mass changes significantly during operation.
Pikkugnome
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How to handle a variable mass system with Lagrangian mechanics? As far as I understand Newtonian mechanics fails, because the object is not constant anymore, it is updated every moment to a new object with different physical properties. I don't immediately see how Lagrangian mechanics can do better.
 
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What makes you think Newtonian mechanics cannot handle variable mass systems? If that were the case it would be difficult to build a rocket to go to the Moon etc.
 
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The first and second law specifically talk about one object. I don't think it is possible to define an object on the fly so to speak as one wishes. What would be the form of the 2nd law, if the object itself was a variable?
 
Pikkugnome said:
The first and second law specifically talk about one object. I don't think it is possible to define an object on the fly so to speak as one wishes. What would be the form of the 2nd law, if the object itself was a variable?
A lot of Internet sources get wrong the treatment of a variable mass system. Not Wikipedia:

https://en.m.wikipedia.org/wiki/Variable-mass_system
 
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