Graduate Can Newton's Method Solve Freer Motion?

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SUMMARY

The discussion centers on the applicability of Newton's Method versus Lagrangian mechanics in solving equations of motion, particularly in scenarios of free motion. It is established that Lagrangian mechanics, including both Lagrange 1 (using Lagrange multipliers for holonomic constraints) and Lagrange 2 (using generalized coordinates), can effectively address systems without constraints. However, challenges arise when dissipative forces, such as friction, are present, complicating the derivation of equations of motion. Thus, while Newton's Method can be employed, Lagrangian mechanics often provides a more straightforward approach in many cases.

PREREQUISITES
  • Understanding of Newton's Method for solving differential equations
  • Familiarity with Lagrangian mechanics, including Lagrange 1 and Lagrange 2 formulations
  • Knowledge of generalized coordinates in classical mechanics
  • Concepts of dissipative forces and their effects on motion
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  • Study the derivation and application of Lagrange multipliers in mechanics
  • Explore generalized coordinates and their advantages in solving motion equations
  • Investigate the impact of dissipative forces on mechanical systems
  • Review case studies where Newton's Method and Lagrangian mechanics are applied
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Students and professionals in physics, mechanical engineering, and applied mathematics, particularly those interested in classical mechanics and the comparison of analytical methods for solving motion equations.

Juli
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Hello everyone,

my question is, if there is a case, where you can't you Langrange (1 or 2) but only Newton to solve the equation of motion?
My guess is, that it might be, when we have no restrictions at all, so a totally free motion.
Does anybody know?
 
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What do you mean by Lagrange 1 and 2? That does not seem like standard nomenclature to me. Please be specific.

Generally, the equations of motion are differential equations and whether they can be solved or not does not depend on the theory you used to derive them. Where you could fail is in arriving at a set of equations of motion.
 
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Usually "Lagrange 1" is the formulation with the (holonomic) constraints treated with Lagrange multipliers, while "Lagrange 2" is the formulation in terms of an appropriate set of "generalized coordinates".
 
Regardless, it should probably be pointed out that Lagrange mechanics is perfectly applicable to systems without constraints. It could even be argued it does better in ease of deriving constants of motion etc. Where you can run into issues is when there are dissipative forces (eg, friction) acting on the system.
 

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