Student Workbook for College Physics

Randy Knight taught introductory physics for 32 years at Ohio State University and California Polytechnic State University, where he is Professor Emeritus of Physics. Professor Knight received a Ph.D. in physics from the University of California, Berkeley and was a post-doctoral fellow at the Harvard-Smithsonian Center for Astrophysics before joining the faculty at Ohio State University. It was at Ohio State that he began to learn about the research in physics education that, many years later, led to Five Easy Lessons: Strategies for Successful Physics Teaching and this book, as well as Physics for Scientists and Engineers: A Strategic Approach. Professor Knight’s research interests are in the fields of laser spectroscopy and environmental science. When he’s not in front of a computer, you can find Randy hiking, sea kayaking, playing the piano, or spending time with his wife Sally and their five cats.Brian Jones has won several teaching awards at Colorado State University during his 30 years teaching in the Department of Physics. His teaching focus in recent years has been the College Physics class, including writing problems for the MCAT exam and helping students review for this test. In 2011, Brian was awarded the Robert A. Millikan Medal of the American Association of Physics Teachers for his work as director of the Little Shop of Physics, a hands-on science outreach program. He is actively exploring the effectiveness of methods of informal science education and how to extend these lessons to the college classroom. Brian has been invited to give workshops on techniques of science instruction throughout the United States and in Belize, Chile, Ethiopia, Azerbaijan, Mexico, Slovenia, Norway, and Namibia. Brian and his wife Carol have dozens of fruit trees and bushes in their yard, including an apple tree that was propagated from a tree in Isaac Newton’s garden.Stuart Field has been interested in science and technology his whole life. While in school he built telescopes, electronic circuits, and computers. After attending Stanford University, he earned a Ph.D. at the University of Chicago, where he studied the properties of materials at ultralow temperatures. After completing a postdoctoral position at the Massachusetts Institute of Technology, he held a faculty position at the University of Michigan. Currently at Colorado State University, Stuart teaches a variety of physics courses, including algebra-based introductory physics, and was an early and enthusiastic adopter of Knight’s Physics for Scientists and Engineers. Stuart maintains an active research program in the area of superconductivity. Stuart enjoys Colorado’s great outdoors, where he is an avid mountain biker; he also plays in local ice hockey leagues.

• Table of Contents PART I Force and Motion OVERVIEW The Science of Physics Representing Motion 1.1 Motion: A First Look1.2 Models and Modeling1.3 Position and Time: Putting Numbers on Nature1.4 Velocity1.5 A Sense of Scale: Significant Figures, Scientific Notation, and Units1.6 Vectors and Motion: A First Look1.7 Where Do We Go from Here?SUMMARYQUESTIONS AND PROBLEMSMotion in One Dimension 2.1 Describing Motion2.2 Uniform Motion2.3 Instantaneous Velocity2.4 Acceleration2.5 Motion with Constant Acceleration2.6 Solving One-Dimensional Motion Problems2.7 Free FallSUMMARYQUESTIONS AND PROBLEMSForces and Newton’s Laws of Motion 4.1 Motion and Forces4.2 A Short Catalog of Forces4.3 Identifying Forces4.4 What Do Forces Do?4.5 Newton’s Second Law4.6 Free-Body Diagrams4.7 Newton’s Third LawSUMMARYQUESTIONS AND PROBLEMSApplying Newton’s Laws 5.1 Equilibrium5.2 Dynamics and Newton’sSecond Law5.3 Mass and Weight5.4 Normal Forces5.5 Friction5.6 Drag5.7 Interacting Objects5.8 Ropes and PulleysSUMMARYQUESTIONS AND PROBLEMSCircular Motion, Orbits, and Gravity 6.1 Uniform Circular Motion6.2 Dynamics of Uniform Circular Motion6.3 Apparent Forces in Circular Motion6.4 Circular Orbits and Weightlessness6.5 Newton’s Law of Gravity6.6 Gravity and OrbitsSUMMARYQUESTIONS AND PROBLEMSRotational Motion 7.1 Describing Circular and Rotational Motion7.2 The Rotation of a Rigid Body7.3 Torque7.4 Gravitational Torque and the Center of Gravity7.5 Rotational Dynamics and Moment of Inertia7.6 Using Newton’s Second Law for Rotation7.7 Rolling MotionSUMMARYQUESTIONS AND PROBLEMSEquilibrium and Elasticity 8.1 Torque and Static Equilibrium8.2 Stability and Balance8.3 Springs and Hooke’s Law8.4 Stretching and Compressing Materials8.5 Forces and Torques in the BodySUMMARYQUESTIONS AND PROBLEMSPART I SUMMARY Force and MotionONE STEP BEYOND Dark Matter and the Structure of the UniversePART I PROBLEMS Detailed Contents PART II Conservation Laws OVERVIEW Why Some Things Stay the Same Momentum 9.1 Impulse9.2 Momentum and the Impulse-Momentum Theorem9.3 Solving Impulse and Momentum Problems9.4 Conservation of Momentum9.5 Inelastic Collisions9.6 Momentum and Collisions in Two Dimensions9.7 Angular MomentumSUMMARYQUESTIONS AND PROBLEMSEnergy and Work 10.1 The Basic Energy Model10.2 Work10.3 Kinetic Energy10.4 Potential Energy10.5 Thermal Energy10.6 Conservation of Energy10.7 Energy Diagrams10.8 Molecular Bonds and Chemical Energy10.9 Energy in Collisions10.10 PowerSUMMARYQUESTIONS AND PROBLEMSUsing Energy 11.1 Transforming Energy11.2 Energy in the Body11.3 Temperature, Thermal Energy, and Heat11.4 The First Law of Thermodynamics11.5 Heat Engines11.6 Heat Pumps11.7 Entropy and the Second Law of Thermodynamics11.8 Systems, Energy, and EntropySUMMARYQUESTIONS AND PROBLEMSPART II SUMMARY Conservation LawsONE STEP BEYOND Order Out of ChaosPART II PROBLEMSPART III Properties of Matter OVERVIEW Beyond the Particle Model Thermal Properties of Matter 12.1 The Atomic Model of Matter12.2 The Atomic Model of an Ideal Gas12.3 Ideal-Gas Processes12.4 Thermal Expansion12.5 Specific Heat and Heat of Transformation12.6 Calorimetry12.7 Specific Heats of Gases12.8 Heat Transfer12.9 DiffusionSUMMARYQUESTIONS AND PROBLEMSFluids 13.1 Fluids and Density13.2 Pressure13.3 Buoyancy13.4 Fluids in Motion13.5 Fluid Dynamics13.6 Viscosity and Poiseuille’s Equation13.7 The Circulatory SystemSUMMARYQUESTIONS AND PROBLEMSPART III SUMMARY Properties of MatterONE STEP BEYOND Size and LifePART III PROBLEMSPART IV Oscillations and Waves OVERVIEW Motion That Repeats Again and Again OSCILLATIONS 14.1 Equilibrium and Oscillation14.2 Linear Restoring Forces and SHM14.3 Describing Simple Harmonic Motion14.4 Energy in Simple Harmonic Motion14.5 Pendulum Motion14.6 Damped Oscillations14.7 Driven Oscillations and ResonanceSUMMARYQUESTIONS AND PROBLEMSTraveling Waves and Sound 15.1 The Wave Model15.2 Traveling Waves15.3 Graphical and MathematicalDescriptions of Waves15.4 Sound and Light Waves15.5 Energy and Intensity15.6 Loudness of Sound15.7 The Doppler Effect and Shock WavesSUMMARYQUESTIONS AND PROBLEMSSuperposition and Standing Waves 16.1 The Principle of Superposition16.2 Standing Waves16.3 Standing Waves on a String16.4 Standing Sound Waves16.5 Speech and Hearing16.6 The Interference of Waves from Two Sources16.7 BeatsSUMMARYQUESTIONS AND PROBLEMSPART IV SUMMARY Oscillations and WavesONE STEP BEYOND Waves in the Earth and the OceanPART IV PROBLEMSPART V Optics OVERVIEW Light Is a Wave Wave Optics 17.1 What Is Light?17.2 The Interference of Light17.3 The Diffraction Grating17.4 Thin-Film Interference17.5 Single-Slit Diffraction17.6 Circular-Aperture DiffractionSUMMARYQUESTIONS AND PROBLEMSRay Optics 18.1 The Ray Model of Light18.2 Reflection18.3 Refraction18.4 Image Formation by Refraction18.5 Thin Lenses: Ray Tracing18.6 Image Formation with Spherical Mirrors18.7 The Thin-Lens EquationSUMMARYQUESTIONS AND PROBLEMSOptical Instruments 19.1 The Camera19.2 The Human Eye19.3 The Magnifier19.4 The Microscope19.5 The Telescope19.6 Color and Dispersion19.7 Resolution of Optical InstrumentsSUMMARYQUESTIONS AND PROBLEMSPART V SUMMARY OpticsONE STEP BEYOND Scanning Confocal MicroscopyPART V PROBLEMSPART VI Electricity and Magnetism OVERVIEW Charges, Currents, and Fields Electric Fields and Forces 20.1 Charges and Forces20.2 Charges, Atoms, and Molecules20.3 Coulomb’s Law20.4 The Concept of the Electric Field20.5 The Electric Field from Arrangements of Charges20.6 Conductors and Electric Fields20.7 Forces and Torques in Electric FieldsSUMMARYQUESTIONS AND PROBLEMSElectric Potential 21.1 Electric Potential Energy and Electric Potential21.2 Sources of Electric Potential21.3 Electric Potential and Conservation of Energy21.4 Calculating the Electric Potential21.5 Connecting Potential and Field21.6 The Electrocardiogram21.7 Capacitance and Capacitors21.8 Energy and CapacitorsSUMMARYQUESTIONS AND PROBLEMSCurrent and Resistance 22.1 A Model of Current22.2 Defining and Describing Current22.3 Batteries and emf22.4 Connecting Potential and Current22.5 Ohm’s Law and Resistor Circuits22.6 Energy and PowerSUMMARYQUESTIONS AND PROBLEMSCircuits 23.1 Circuit Elements and Diagrams23.2 Kirchhoff’s Laws23.3 Series and Parallel Circuits23.4 Measuring Voltage and Current23.5 More Complex Circuits23.6 Capacitors in Parallel and Series23.7 RC Circuits23.8 Electricity in the Nervous SystemSUMMARYQUESTIONS AND PROBLEMSMagnetic Fields and Forces 24.1 Magnetism24.2 The Magnetic Field24.3 Electric Currents Also Create Magnetic Fields24.4 Calculating the Magnetic Field Due to a Current24.5 Magnetic Fields Exert Forces on Moving ChargesDetailed Contents24.6 Magnetic Fields Exert Forces on Currents24.7 Magnetic Fields Exert Torques on Dipoles24.8 Magnets and Magnetic MaterialsSUMMARYQUESTIONS AND PROBLEMSEM Induction and EM Waves 25.1 Induced Currents25.2 Motional emf25.3 Magnetic Flux and Lenz’s Law25.4 Faraday’s Law25.5 Electromagnetic Waves25.6 The Photon Model of Electromagnetic Waves25.7 The Electromagnetic SpectrumSUMMARYQUESTIONS AND PROBLEMSAC Electricity 26.1 Alternating Current26.2 AC Electricity and Transformers26.3 Household Electricity26.4 Biological Effects and Electrical Safety26.5 Capacitor Circuits26.6 Inductors and Inductor Circuits26.7 Oscillation CircuitsSUMMARYQUESTIONS AND PROBLEMSPART VI SUMMARY Electricity and MagnetismONE STEP BEYOND The Greenhouse Effect and Global WarmingPART VI PROBLEMSPART VII Modern Physics OVERVIEW New Ways of Looking at the World Relativity 27.1 Relativity: What’s It All About?27.2 Galilean Relativity27.3 Einstein’s Principle of Relativity27.4 Events and Measurements27.5 The Relativity of Simultaneity27.6 Time Dilation27.7 Length Contraction27.8 Velocities of Objects in Special Relativity27.9 Relativistic Momentum27.10 Relativistic EnergySUMMARYQUESTIONS AND PROBLEMSQuantum Physics 28.1 X Rays and X-Ray Diffraction28.2 The Photoelectric Effect28.3 Photons28.4 Matter Waves28.5 Energy Is Quantized28.6 Energy Levels and Quantum Jumps28.7 The Uncertainty Principle28.8 Applications and Implications of Quantum TheorySUMMARYQUESTIONS AND PROBLEMSAtoms and Molecules 29.1 Spectroscopy29.2 Atoms29.3 Bohr’s Model of Atomic Quantization29.4 The Bohr Hydrogen Atom29.5 The Quantum-Mechanical Hydrogen Atom29.6 Multi-electron Atoms29.7 Excited States and Spectra29.8 Molecules29.9 Stimulated Emission and LasersSUMMARYQUESTIONS AND PROBLEMSNuclear Physics 30.1 Nuclear Structure30.2 Nuclear Stability30.3 Forces and Energy in the Nucleus30.4 Radiation and Radioactivity30.5 Nuclear Decay and Half-Lives30.6 Medical Applications of Nuclear Physics30.7 The Ultimate Building Blocks of MatterSUMMARYQUESTIONS AND PROBLEMSPART VII SUMMARY Modern PhysicsONE STEP BEYOND The Physics of Very Cold AtomsPART VII PROBLEMSAppendix A Mathematics Review Appendix B Periodic Table of Elements Appendix C Atomic and Nuclear Data Answers to Odd-Numbered Problems