Lagrangian vs Newtonian Mechanics

Abide By Reason
Aug 29, 2025
5 notes
5 Notes in this Video

Newtonian vs Lagrangian Views of Simple Harmonic Motion

SimpleHarmonicMotion NewtonianMechanics LagrangianMechanics
02:30

Abide by Reason contrasts Newtonian and Lagrangian formulations for students who know (F=ma) and springs but not why we’d switch to energies and Lagrangians.

Lagrangian as Kinetic Minus Potential and Its Energy-Space Geometry

Lagrangian EnergySpace KMinusU
08:30

This note is for learners puzzled by the seemingly arbitrary definition (L = T - U) and wanting a more intuitive picture.

Action as Area Under Lagrangian and Principle of Least Action

Action LeastAction EulerLagrange
13:00

Abide by Reason clarifies the meaning of action for students who have seen (S = \int L,dt) but lack a geometric picture.

Advantages of Lagrangian Mechanics Over Force-Based Newtonian Methods

LagrangianAdvantages GeneralizedCoordinates Constraints
18:00

This note targets learners deciding when to use Newton’s vector-force equations and when to switch to a Lagrangian formulation.

Relationship Between Lagrangian and Hamiltonian Descriptions of Mechanics

HamiltonianMechanics EnergyConservation PhaseSpace
22:00

Abide by Reason briefly contrasts Lagrangian and Hamiltonian mechanics for viewers progressing from configuration-space to phase-space formulations.