PHYSICAL CONSTANTS CONSTANT SYMBOL THREE-FIGURE VALUE BEST KNOWN VALUE* Speed of light c 3.00 * 108 m/s 299,792,458 m/s (exact) Elementary charge e 1.60*10-19 C 1.602 176 634 * 10-19 C (exact) Electron mass me 9.11 * 10-31 kg 9.109 383 56 11 * 10-31 kg Proton mass m 1.67 * 10-27 kg 1.672 621 898 21 * 10-27 kg p Gravitational constant G 6.67 * 10-11 N#m2/kg2 6.67408 31 1* 120-11 N#m2/kg2 1 2 Permeability constant m 1.26 * 10-6 N/A2 H/m 12.566 370 616 9 29 * 10-7 N/A2 Permittivity constant P00 8.85 * 10-12 C2/N#m2 F/m 8.854 1817 8215 8 20 * 10-7 C2/ N#m2 1 2 1 2 Boltzmann’s constant k 1.38 * 10-23 J/K 1.380 649 * 10-23 J/K (exact) 1 2 1 2 # Universal gas constant R 8.31 J/Kmol N k (exact) A Stefan–Boltzmann constant s 5.67 * 10-8 W/m2#K4 5.670 367 13 * 10-8 W/m2#K4 Planck’s constant h = 2pU 6.63 * 10-34 J#s 6.626 070 15 * 10-34 J#s (exact) Avogadro’s number NA 6.02 * 1023 mol-1 6.022 1401 762* 1023 mol-1 (exact) Bohr radius 1 a0 2 5.29 * 10-11 m 5.291 772 085 9 36 * 10-11 m *Parentheses indicate uncertainties in last decimal places. Source: U.S. National Institute of Standards and Technology, 2014, 2019 values 1 2 SI PREFIXES THE GREEK ALPHABET UPPERCASE LOWERCASE POWER PREFIX SYMBOL 1024 yotta Y Alpha Α a 1021 zetta Z Beta Β b 1018 exa E Gamma Γ g 1015 peta P Delta ∆ d 1012 tera T Epsilon Ε P 109 giga G Zeta Ζ z Eta H h 106 mega M Theta ∫ u 103 kilo k Iota Ι i 102 hecto h Kappa Κ k 101 deca da Lambda Λ l 100 — — Mu Μ m 10-1 deci d Nu Ν n 10-2 centi c Xi Ξ j Omicron Ο o 10-3 milli m Pi Π p 10-6 micro μ Rho Ρ r 10-9 nano n Sigma Σ s 10-12 pico p Tau Τ t 10-15 femto f Upsilon Υ y 10-18 atto a Phi Φ f 10-21 zepto z Chi Χ x Psi Ψ c 10-24 yocto y Omega Ω v Conversion Factors (more conversion factors in Appendix C) Length Mass, energy, force Pressure 1 in = 2.54 cm 1 u = 1.661 * 10-27 kg 1 atm = 101.3 kPa = 760 mm Hg 1 mi = 1.609 km 1 cal = 4.184 J 1 atm = 14.7 lb/in2 1 ft = 0.3048 m 1 Btu = 1.054 kJ Rotation and angle 1 light year = 9.46 * 1015 m 1 kWh = 3.6 MJ Velocity 1 eV = 1.602 * 10-19 J 11 rraedv == 138600°°/p= =2p5 r7a.d3° 1 pound lb = 4.448 N 1 mi/h = 0.447 m/s 1 rev/s = 60 rpm = weight of 0.454 kg 1 m/s = 2.24 mi/h = 3.28 ft/s 1 2 Magnetic field Time 1 gauss = 10-4 T 1 day = 86,400 s 1 year = 3.156 * 107 s CVR_WOLF8559_04_SE_IFC.indd 677 11/13/18 9:16 PM VOLUME ONE Chapters 1–19 Essential University Physics FOURTH EDITION Richard Wolfson Middlebury College A01_WOLF8559_04_SE_FM_Vol1.indd 1 11/16/18 5:49 AM Physics & Astronomy Portfolio Analyst: Ian Desrosiers Art Coordinator: Troutt Visual Services Director of Physical Science Portfolio: Jeanne Zalesky Design Manager: Maria Guglielmo Walsh Content Producer: Tiffany Mok Interior Designer: Wee Design Group Managing Producer: Kristen Flathman Cover Designer: Wee Design Group Courseware Director, Content Development: Illustrators: Troutt Visual Services Barbara Yien Rights & Permissions Project Manager: Carol Ylanan Courseware Analyst: Coleen Morrison and John Paul Belciña Development Editor: John Murdzek Rights & Permissions Management: SPi Global Courseware Editorial Assistant: Frances Lai Manufacturing Buyer: Stacey Weinberger Rich Media Content Producer: Alison Candlin Director of Field Marketing: Tim Galligan Mastering Media Producer: David Hoogewerff Director of Product Marketing: Alison Rona Full-Service Vendor: Integra Software Services Field Marketing Manager: Yez Alayan Copyeditor: Daniel Nighting Product Marketing Manager: Elizabeth Bell Compositor: Integra Software Services Cover Photo Credit: Technotr/Vetta/Getty Images Copyright © 2020, 2016, 2012 Pearson Education, Inc. 221 River Street, Hoboken, NJ 07030. All Rights Reserved. Printed in the United States of America. This publication is protected by copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise. For informa- tion regarding permissions, request forms and the appropriate contacts within the Pearson Education Global Rights & Permissions department. Attributions of third party content appear on page C-1, which constitutes an extension of this copyright page. PEARSON, ALWAYS LEARNING, MasteringTM Physics are exclusive trademarks in the U.S. and/or other countries owned by Pearson Education, Inc. or its affiliates. Unless otherwise indicated herein, any third-party trademarks that may appear in this work are the property of their respective owners and any references to third-party trade- marks, logos or other trade dress are for demonstrative or descriptive purposes only. Such references are not intended to imply any sponsorship, endorsement, authorization, or pro- motion of Pearson’s products by the owners of such marks, or any relationship between the owner and Pearson Education, Inc. or its affiliates, authors, licensees or distributors. Library of Congress Cataloging-in-Publication Data Names: Wolfson, Richard, author. Title: Essential university physics / Richard Wolfson. Description: Fourth edition. | New York : Pearson Education, [2020] | Includes index. Identifiers: LCCN 2018031561| ISBN 9780134988559 (softcover : v. 1) | ISBN 9780134988566 (softcover : v. 2) Subjects: LCSH: Physics—Textbooks. Classification: LCC QC21.3 .W65 2020 | DDC 530—dc23 LC record available at https://lccn.loc.gov/2018031561 (Student edition) ISBN 10: 0-134-98855-8 ISBN 13: 978-0-134-98855-9 (Looseleaf edition) ISBN 10: 0-135-26466-9 www.pearson.com ISBN 13: 978-0-135-26466-9 A01_WOLF8559_04_SE_FM_Vol1.indd 2 11/16/18 5:49 AM Brief Contents Chapter 22 Electric Potential 414 Chapter 1 Doing Physics 1 Chapter 23 Electrostatic Energy and Capacitors 434 Chapter 24 Electric Current 449 PART ONE Mechanics 15 Chapter 25 Electric Circuits 467 Chapter 2 Motion in a Straight Line 16 Chapter 26 Magnetism: Force and Field 488 Chapter 3 Motion in Two and Three Dimensions 34 Chapter 27 Electromagnetic Induction 516 Chapter 4 Force and Motion 54 Chapter 28 Alternating-Current Circuits 545 Chapter 5 Using Newton’s Laws 74 Chapter 29 Maxwell’s Equations and Electromagnetic Waves 564 Chapter 6 Energy, Work, and Power 94 Chapter 7 Conservation of Energy 113 PART FIVE Chapter 8 Gravity 134 Optics 588 Chapter 9 Systems of Particles 150 Chapter 30 Reflection and Refraction 589 Chapter 10 Rotational Motion 175 Chapter 31 Images and Optical Instruments 603 Chapter 11 Rotational Vectors and Angular Chapter 32 Interference and Diffraction 624 Momentum 196 Chapter 12 Static Equilibrium 211 PART SIX Modern Physics 647 PART TWO Chapter 33 Relativity 648 Oscillations, Waves, and Fluids 228 Chapter 34 Particles and Waves 674 Chapter 13 Oscillatory Motion 229 Chapter 35 Quantum Mechanics 694 Chapter 14 Wave Motion 250 Chapter 36 Atomic Physics 711 Chapter 15 Fluid Motion 274 Chapter 37 Molecules and Solids 730 Chapter 38 Nuclear Physics 749 PART THREE Thermodynamics 294 Chapter 39 From Quarks to the Cosmos 777 Chapter 16 Temperature and Heat 295 Chapter 17 The Thermal Behavior of Matter 313 Appendix A. Mathematics A-1 Chapter 18 Heat, Work, and the First Law of Appendix B. The International System of Units (SI) A-9 Thermodynamics 328 Appendix C. Conversion Factors A-11 Chapter 19 The Second Law of Thermodynamics 345 Appendix D. The Elements A-13 Appendix E. Astrophysical Data A-16 PART FOUR Electromagnetism 367 Answers to Odd-Numbered Problems A-17 Credits C-1 Chapter 20 Electric Charge, Force, and Field 368 Index I-2 Chapter 21 Gauss’s Law 389 iii A01_WOLF8559_04_SE_FM_Vol1.indd 3 11/16/18 5:49 AM Detailed Contents Volume 1 contains Chapters 1–19 5.3 Circular Motion 79 Volume 2 contains Chapters 20–39 5.4 Friction 83 Chapter 1 Doing Physics 1 5.5 Drag Forces 88 1.1 Realms of Physics 1 Chapter 6 Energy, Work, and Power 94 1.2 Measurements and Units 2 6.1 Energy 94 1.3 Working with Numbers 5 6.2 Work 96 1.4 Strategies for Learning Physics 8 6.3 Forces That Vary 99 6.4 Kinetic Energy 103 PART ONE 6.5 Power 105 Mechanics 15 Chapter 7 Conservation of Energy 113 Chapter 2 Motion in a Straight Line 16 7.1 Conservative and Nonconservative Forces 114 2.1 Average Motion 16 7.2 Potential Energy 115 2.2 Instantaneous Velocity 18 7.3 Conservation of Mechanical Energy 119 2.3 Acceleration 20 7.4 Nonconservative Forces 122 2.4 Constant Acceleration 22 7.5 Conservation of Energy 124 2.5 The Acceleration of Gravity 25 7.6 Potential-Energy Curves 125 2.6 When Acceleration Isn’t Constant 27 Chapter 8 Gravity 134 Chapter 3 Motion in Two and Three Dimensions 34 8.1 Toward a Law of Gravity 134 3.1 Vectors 34 8.2 Universal Gravitation 135 3.2 Velocity and Acceleration Vectors 37 8.3 Orbital Motion 137 3.3 Relative Motion 38 8.4 Gravitational Energy 140 3.4 Constant Acceleration 40 8.5 The Gravitational Field 144 3.5 Projectile Motion 41 Chapter 9 Systems of Particles 150 3.6 Uniform Circular Motion 46 9.1 Center of Mass 150 Chapter 4 Force and Motion 54 9.2 Momentum 156 4.1 The Wrong Question 54 9.3 Kinetic Energy of a System 160 4.2 Newton’s First and Second Laws 55 9.4 Collisions 161 4.3 Forces 59 9.5 Totally Inelastic Collisions 162 4.4 The Force of Gravity 60 9.6 Elastic Collisions 164 4.5 Using Newton’s Second Law 62 Chapter 10 Rotational Motion 175 4.6 Newton’s Third Law 65 10.1 Angular Velocity and Acceleration 175 Chapter 5 Using Newton’s Laws 74 10.2 Torque 178 5.1 Using Newton’s Second Law 74 10.3 Rotational Inertia and the Analog of Newton’s 5.2 Multiple Objects 77 Law 180 iv A01_WOLF8559_04_SE_FM_Vol1.indd 4 11/16/18 5:49 AM Contents v 10.4 Rotational Energy 185 15.4 Fluid Dynamics 280 10.5 Rolling Motion 187 15.5 Applications of Fluid Dynamics 283 Chapter 11 Rotational Vectors and Angular 15.6 Viscosity and Turbulence 287 Momentum 196 11.1 Angular Velocity and Acceleration Vectors 196 PART THREE Thermodynamics 294 11.2 Torque and the Vector Cross Product 197 11.3 Angular Momentum 199 Chapter 16 Temperature and Heat 295 11.4 Conservation of Angular Momentum 201 16.1 Heat, Temperature, and Thermodynamic Equilibrium 295 11.5 Gyroscopes and Precession 203 16.2 Heat Capacity and Specific Heat 297 Chapter 12 Static Equilibrium 211 16.3 Heat Transfer 299 12.1 Conditions for Equilibrium 211 16.4 Thermal-Energy Balance 305 12.2 Center of Gravity 213 Chapter 17 The Thermal Behavior of Matter 313 12.3 Examples of Static Equilibrium 214 17.1 Gases 313 12.4 Stability 216 17.2 Phase Changes 318 17.3 Thermal Expansion 321 PART TWO Oscillations, Waves, and Fluids 228 Chapter 18 Heat, Work, and the First Law of Thermodynamics 328 Chapter 13 Oscillatory Motion 229 18.1 The First Law of Thermodynamics 328 13.1 Describing Oscillatory Motion 230 18.2 Thermodynamic Processes 330 13.2 Simple Harmonic Motion 231 18.3 Specific Heats of an Ideal Gas 338 13.3 Applications of Simple Harmonic Motion 234 Chapter 19 The Second Law of Thermodynamics 345 13.4 Circular Motion and Harmonic Motion 238 19.1 Reversibility and Irreversibility 345 13.5 Energy in Simple Harmonic Motion 239 19.2 The Second Law of Thermodynamics 346 13.6 Damped Harmonic Motion 241 19.3 Applications of the Second Law 350 13.7 Driven Oscillations and Resonance 242 19.4 Entropy and Energy Quality 353 Chapter 14 Wave Motion 250 14.1 Waves and Their Properties 250 PART FOUR 14.2 Wave Math 252 Electromagnetism 367 14.3 Waves on a String 254 Chapter 20 Electric Charge, Force, and Field 368 14.4 Wave Energy 255 20.1 Electric Charge 368 14.5 Sound Waves 257 20.2 Coulomb’s Law 369 14.6 Interference 258 20.3 The Electric Field 373 14.7 Reflection and Refraction 261 20.4 Fields of Charge Distributions 375 14.8 Standing Waves 263 20.5 Matter in Electric Fields 380 14.9 The Doppler Effect and Shock Waves 265 Chapter 21 Gauss’s Law 389 Chapter 15 Fluid Motion 274 21.1 Electric Field Lines 389 15.1 Density and Pressure 274 21.2 Electric Field and Electric Flux 391 15.2 Hydrostatic Equilibrium 275 21.3 Gauss’s Law 394 15.3 Archimedes’ Principle and Buoyancy 278 21.4 Using Gauss’s Law 396 A01_WOLF8559_04_SE_FM_Vol1.indd 5 11/16/18 5:49 AM vi Contents 21.5 Fields of Arbitrary Charge Distributions 403 27.5 Magnetic Energy 533 21.6 Gauss’s Law and Conductors 404 27.6 Induced Electric Fields 536 Chapter 22 Electric Potential 414 Chapter 28 Alternating-Current Circuits 545 22.1 Electric Potential Difference 414 28.1 Alternating Current 545 22.2 Calculating Potential Difference 418 28.2 Circuit Elements in AC Circuits 546 22.3 Potential Difference and the Electric Field 424 28.3 LC Circuits 550 22.4 Charged Conductors 427 28.4 Driven RLC Circuits and Resonance 553 Chapter 23 Electrostatic Energy and Capacitors 434 28.5 Power in AC Circuits 556 23.1 Electrostatic Energy 434 28.6 Transformers and Power Supplies 557 23.2 Capacitors 435 Chapter 29 Maxwell’s Equations and Electromagnetic Waves 564 23.3 Using Capacitors 437 29.1 The Four Laws of Electromagnetism 564 23.4 Energy in the Electric Field 441 29.2 Ambiguity in Ampère’s Law 565 Chapter 24 Electric Current 449 29.3 Maxwell’s Equations 567 24.1 Electric Current 449 29.4 Electromagnetic Waves 568 24.2 Conduction Mechanisms 452 29.5 Properties of Electromagnetic Waves 572 24.3 Resistance and Ohm’s Law 456 29.6 The Electromagnetic Spectrum 576 24.4 Electric Power 458 29.7 Producing Electromagnetic Waves 577 24.5 Electrical Safety 459 29.8 Energy and Momentum in Electromagnetic Chapter 25 Electric Circuits 467 Waves 578 25.1 Circuits, Symbols, and Electromotive Force 467 25.2 Series and Parallel Resistors 468 PART FIVE 25.3 Kirchhoff’s Laws and Multiloop Circuits 474 Optics 588 25.4 Electrical Measurements 476 Chapter 30 Reflection and Refraction 589 25.5 Capacitors in Circuits 477 30.1 Reflection 589 Chapter 26 Magnetism: Force and Field 488 30.2 Refraction 591 26.1 What Is Magnetism? 488 30.3 Total Internal Reflection 593 26.2 Magnetic Force and Field 489 30.4 Dispersion 595 26.3 Charged Particles in Magnetic Fields 491 Chapter 31 Images and Optical Instruments 603 26.4 The Magnetic Force on a Current 493 31.1 Images with Mirrors 603 26.5 Origin of the Magnetic Field 495 31.2 Images with Lenses 608 26.6 Magnetic Dipoles 498 31.3 Refraction in Lenses: The Details 611 26.7 Magnetic Matter 501 31.4 Optical Instruments 614 26.8 Ampère’s Law 503 Chapter 32 Interference and Diffraction 624 Chapter 27 Electromagnetic Induction 516 32.1 Coherence and Interference 624 27.1 Induced Currents 516 32.2 Double-Slit Interference 626 27.2 Faraday’s Law 518 32.3 Multiple-Slit Interference and Diffraction 27.3 Induction and Energy 522 Gratings 629 27.4 Inductance 528 32.4 Interferometry 633 A01_WOLF8559_04_SE_FM_Vol1.indd 6 11/16/18 5:49 AM Contents vii 32.5 Huygens’ Principle and Diffraction 635 36.3 The Exclusion Principle 718 32.6 The Diffraction Limit 638 36.4 Multielectron Atoms and the Periodic Table 719 36.5 Transitions and Atomic Spectra 723 PART SIX Chapter 37 Molecules and Solids 730 Modern Physics 647 37.1 Molecular Bonding 730 Chapter 33 Relativity 648 37.2 Molecular Energy Levels 732 33.1 Speed c Relative to What? 649 37.3 Solids 735 33.2 Matter, Motion, and the Ether 649 37.4 Superconductivity 741 33.3 Special Relativity 651 Chapter 38 Nuclear Physics 749 33.4 Space and Time in Relativity 652 38.1 Elements, Isotopes, and Nuclear Structure 749 33.5 Simultaneity Is Relative 657 38.2 Radioactivity 754 33.6 The Lorentz Transformations 659 38.3 Binding Energy and Nucleosynthesis 760 33.7 Energy and Momentum in Relativity 662 38.4 Nuclear Fission 762 33.8 Electromagnetism and Relativity 666 38.5 Nuclear Fusion 768 33.9 General Relativity 667 Chapter 39 From Quarks to the Cosmos 777 Chapter 34 Particles and Waves 674 39.1 Particles and Forces 777 34.1 Toward Quantum Theory 674 39.2 Particles and More Particles 778 34.2 Blackbody Radiation 675 39.3 Quarks and the Standard Model 782 34.3 Photons 677 39.4 Unification 785 34.4 Atomic Spectra and the Bohr Atom 680 39.5 The Evolving Universe 787 34.5 Matter Waves 684 34.6 The Uncertainty Principle 686 APPENDICES 34.7 Complementarity 688 Appendix A Mathematics A-1 Chapter 35 Quantum Mechanics 694 Appendix B The International System of Units (SI) A-9 35.1 Particles, Waves, and Probability 695 Appendix C Conversion Factors A-11 35.2 The Schrödinger Equation 696 Appendix D The Elements A-13 35.3 Particles and Potentials 698 Appendix E Astrophysical Data A-16 35.4 Quantum Mechanics in Three Dimensions 705 Answers to Odd-Numbered Problems A-17 35.5 Relativistic Quantum Mechanics 705 Credits C-1 Chapter 36 Atomic Physics 711 Index I-2 36.1 The Hydrogen Atom 711 36.2 Electron Spin 715 A01_WOLF8559_04_SE_FM_Vol1.indd 7 11/16/18 5:49 AM About the Author Richard Wolfson Richard Wolfson is the Benjamin F. Wissler Professor of Physics at Middlebury College, where he has taught since 1976. He did undergraduate work at MIT and S warthmore College, and he holds an M.S. from the University of Michigan and a Ph.D. from Dartmouth. His ongoing research on the Sun’s corona and climate change has taken him to s abbaticals at the National Center for Atmospheric Research in Boulder, Colorado; St. Andrews University in Scotland; and Stanford University. Rich is a committed and passionate teacher. This is reflected in his many p ublications for students and the general public, including the video series Einstein’s Relativity and the Quantum Revolution: Modern Physics for Nonscientists (The Teaching Company, 1999), Physics in Your Life (The Teaching Company, 2004), Physics and Our Universe: How It All Works (The Teaching Company, 2011), and Understanding Modern Electronics (The Teaching Company, 2014); books Nuclear Choices: A Citizen’s Guide to Nuclear Technology (MIT Press, 1993), Simply Einstein: Relativity Demystified (W. W. Norton, 2003), and Energy, Environment, and Climate (W. W. Norton, third edition, 2018); and articles for Scientific American and the World Book Encyclopedia. Outside of his research and teaching, Rich enjoys hiking, canoeing, gardening, cooking, and watercolor painting. viii A01_WOLF8559_04_SE_FM_Vol1.indd 8 11/16/18 5:49 AM