ANALYTICAL MECHANICS. LOUIS N. HAND and JANET D. FINCH CAMBRIDGE UNIVERSITY PRESS

Transcription

1 ANALYTICAL MECHANICS LOUIS N. HAND and JANET D. FINCH CAMBRIDGE UNIVERSITY PRESS

2 Preface xi 1 LAGRANGIAN MECHANICS l 1.1 Example and Review of Newton's Mechanics: A Block Sliding on an Inclined Plane Using Virtual Work to Solve the Same Problem Solving for the Motion of a Heavy Bead Sliding on a Rotating Wire Toward a General Formula: Degrees of Freedom and Types of Constraints Generalized Velocities: How to "Cancel the Dots" Virtual Displacements and Virtual Work - Generalized Forces Kinetic Energy as a Function of the Generalized Coordinates and Velocities Conservative Forces: Definition of the Lagrangian L Reference Frames Definition of the Hamiltonian How to Get Rid of Ignorable Coordinates Discussion and Conclusions - What's Next after You Get the EOM? An Example of a Solved Problem 24 Summary of Chapter 1 25 Problems 26 Appendix A. About Nonholonomic Constraints 36 Appendix B. More about Conservative Forces 41 2 VARIATIONAL CALCULUS AND ITS APPLICATION TO MECHANICS History The Euler Equation Relevance to Mechanics Systems with Several Degrees of Freedom Why Use the Variational Approach in Mechanics? Lagrange Multipliers 56

3 2.7 Solving Problems with Explicit Holonomic Constraints Nonintegrable Nonholonomic Constraints - A Method that Works Postscript on the Euler Equation with More Than One Independent Variable 65 Summary of Chapter 2 65 Problems 66 Appendix. About Maupertuis and What Came to Be Called "Maupertuis' Principle" 75 LINEAR OSCILLATORS Stable or Unstable Equilibrium? Simple Harmonic Oscillator Damped Simple Harmonic Oscillator (DSHO) An Oscillator Driven by an External Force Driving Force Is a Step Function Finding the Green's Function for the SHO Adding up the Delta Functions - Solving the Arbitary Force Driving an Oscillator in Resonance Relative Phase of the DSHO Oscillator with Sinusoidal Drive 110 Summary of Chapter Problems 114 ONE-DIMENSIONAL SYSTEMS: CENTRAL FORCES AND THE KEPLER PROBLEM The Motion of a "Generic" One-Dimensional System The Grandfather's Clock The History of the Kepler Problem Solving the Central Force Problem The Special Case of Gravitational Attraction Interpretation of Orbits Repulsive \ Forces 151 Summary of Chapter Problems 156 Appendix. Tables of Astrophysical Data 167 NOETHER'S THEOREM AND HAMILTONIAN DYNAMICS Discovering Angular Momentum Conservation from Rotational Invariance Noether's Theorem Hamiltonian Dynamics The Legendre Transformation Hamilton's Equations of Motion Liouville's Theorem Momentum Space 189

4 VII 5.8 Hamiltonian Dynamics in Accelerated Systems 190 Summary of Chapter Problems 196 Appendix A. A General Proof of Liouville's Theorem Using the Jacobian 202 Appendix B. Poincare Recurrence Theorem 204 THEORETICAL MECHANICS: FROM CANONICAL TRANSFORMATIONS TO ACTION-ANGLE VARIABLES Canonical Transformations Discovering Three New Forms of the Generating Function Poisson Brackets Hamilton-Jacobi Equation Action-Angle Variables for 1-D Systems Integrable Systems Invariant Tori and Winding Numbers 237 Summary of Chapter Problems 240 Appendix. What Does "Symplectic" Mean? 248 ROTATING COORDINATE SYSTEMS What Is a Vector? Review: Infinitesimal Rotations and Angular Velocity Finite Three-Dimensional Rotations Rotated Reference Frames Rotating Reference Frames The Instantaneous Angular Velocity a> Fictitious Forces The Tower of Pisa Problem Why Do Hurricane Winds Rotate? Foucault Pendulum 272 Summary of Chapter Problems 276 THE DYNAMICS OF RIGID BODIES Kinetic Energy of a Rigid Body The Moment of Inertia Tensor Angular Momentum of a Rigid Body The Euler Equations for Force-Free Rigid Body Motion Motion of a Torque-Free Symmetric Top Force-Free Precession of the Earth: The "Chandler Wobble" Definition of Euler Angles Finding the Angular Velocity Motion of Torque-Free Asymmetric Tops: Poinsot Construction 305

5 8.10 The Heavy Symmetrie Top Precession of the Equinoxes Mach's Principle 323 Summary of Chapter Problems 326 Appendix A. What Is a Tensor? 333 Appendix B. Symmetric Matrices Can Always Be Diagonalized by "Rotating the Coordinates" 336 Appendix C. Understanding the Earth's Equatorial Bulge 339 THE THEORY OF SMALL VIBRATIONS Two Coupled Pendulums Exact Lagrangian for the Double Pendulum Single Frequency Solutions to Equations of Motion Superimposing Different Modes; Complex Mode Amplitudes Linear Triatomic Molecule Why the Method Always Works N Point Masses Connected by a String 367 Summary of Chapter Problems 373 Appendix. What Is a Cofactor? 380 APPROXIMATE SOLUTIONS TO NONANALYTIC PROBLEMS Stability of Mechanical Systems Parametric Resonance Lindstedt-Poincare Perturbation Theory Driven Anharmonic Oscillator 401 Summary of Chapter Problems 413 CHAOTIC DYNAMICS Conservative Chaos - The Double Pendulum: A Hamiltonian System with Two Degrees of Freedom The Poincare Section KAM Tori: The Importance of Winding Number Irrational Winding Numbers Poincare-Birkhoff Theorem Linearizing Near a Fixed Point: The Tangent Map and the Stability Matrix Following Unstable Manifolds: Homoclinic Tangles Lyapunov Exponents Global Chaos for the Double Pendulum Effect of Dissipation Damped Driven Pendulum 453

6 IX Fractals Chaos in the Solar System 468 Student Projects 474 Appendix. The Logistic Map: Period-Doubling Route to Chaos; Renormalization SPECIAL RELATIVITY Space-Time Diagrams The Lorentz Transformation Simultaneity Is Relative What Happens to у and z if We Move Parallel to the X Axis? Velocity Transformation Rules Observing Light Waves What Is Mass? Rest Mass Is a Form of Energy How Does Momentum Transform? More Theoretical "Evidence" for the Equivalence of Mass and Energy Mathematics of Relativity: Invariants and Four-Vectors A Second Look at the Energy-Momentum Four-Vector Why Are There Both Upper and Lower Greek Indices? Relativistic Lagrangian Mechanics What Is the Lagrangian in an Electromagnetic Field? Does a Constant Force Cause Constant Acceleration? Derivation of the Lorentz Force from the Lagrangian Relativistic Circular Motion 539 Summary of Chapter Problems 541 Appendix. The Twin Paradox 554 Bibliography 559 References 563 Index 565