Physics for dummies

Introduction Part I: Putting Physics into Motion. Chapter 1: Using Physics to Understand Your World. Chapter 2: Understanding Physics Fundamentals. Chapter 3: Exploring the Need for Speed. Chapter 4: Following Directions: Which Way Are You Going? Part II: May the Forces of Physics Be with You. Chapter 5: When Push Comes to Shove: Force. Chapter 6: What a Drag: Inclined Planes and Friction. Chapter 7: Circling around Circular Motions and Orbits. Part III: Manifesting the Energy to Work. Chapter 8: Getting Some Work out of Physics. Chapter 9: Putting Objects in Motion: Momentum and Impulse. Chapter 10: Winding Up with Angular Kinetics. Chapter 11: Round and Round with Rotational Dynamics. Chapter 12: Springs-n-Things: Simple Harmonic Motion. Part IV: Laying Down the Laws of Thermodynamics. Chapter 13: Turning Up the Heat with Thermodynamics. Chapter 14: Here, Take My Coat: Heat Transfer in Solids and Gases. Chapter 15: When Heat and Work Collide: The Laws of Thermodynamics. Part V: Getting a Charge out of Electricity and Magnetism. Chapter 16: Zapping Away with Static Electricity. Chapter 17: Giving Electrons a Push with Circuits. Chapter 18: Magnetism: More than Attraction. Chapter 19: Keeping the Current Going with Voltage. Chapter 20: Shedding Some Light on Mirrors and Lenses. Part VI: The Part of Tens. Chapter 21: Ten Amazing Insights on Relativity. Chapter 22: Ten Wild Physics Theories. Glossary. Index Does just thinking about the laws of motion make your head spin? Does studying electricity short your circuits? Do the complexities of thermodynamics cool your enthusiasm?Thanks to this book, you don’t have to be Einstein to understand physics. As you read about Newton’s Laws, Kepler’s Laws, Hooke’s Law, Ohm’s Law, and others, you’ll appreciate the For Dummies law: The easier we make it, the faster people understand it and the more they enjoy it! Whether you’re taking a class, helping kids with homework, or trying to find out how the world works, this book helps you understand basic physics. It covers:Measurements, units, and significant figuresForces such as displacement, speed, and accelerationVectors and physics notationMotion, energy, and waves (sound, light, wave-particle)Solids, liquids, and gasesThermodynamicsElectromagnetismRelativityAtomic and nuclear structuresSteven Holzner, Ph.D. earned his B.S. at MIT and his Ph.D. at Cornell, where he taught Physics 101 and 102 for over 10 years. He livens things up with cool physics facts, real-world examples, and simple experiments that will heighten your enthusiasm for physics and science. The book ends with some out-of-this world physics that will set your mind in motion:The possibility of wormholes in spaceThe Big BangHow the gravitational pull of black holes is too strong for even light to escapeMay the Force be with you! Physics For Dummies 3 About the Author 5 Dedication 5 Author’s Acknowledgments 5 Contents at a Glance 7 Table of Contents 9 Introduction 17 About This Book 17 Conventions Used in This Book 18 What You’re Not to Read 18 Foolish Assumptions 18 How This Book Is Organized 18 Icons Used in This Book 20 Where to Go from Here 20 Part 1: Putting Physics into Motion 21 Chapter 1: Using Physics to Understand YourWorld 23 What Physics Is All About 23 Observing Objects in Motion 24 Absorbing the Energy Around You 25 Feeling Hot but Not Bothered 26 Playing with Charges and Magnets 26 Preparing for the Wild, Wild Physics Coming Up 27 Chapter 2: Understanding Physics Fundamentals 29 Don’t Be Scared, It’s Only Physics 30 Measuring the World Around You and Making Predictions 31 Eliminating Some Zeros: Using Scientific Notation 36 Checking the Precision of Measurements 37 Arming Yourself with Basic Algebra 39 Tackling a Little Trig 39 Chapter 3: Exploring the Need for Speed 41 Dissecting Displacement 42 Speed Specifics: What Is Speed, Anyway? 45 Speeding Up (or Down): Acceleration 49 Relating Acceleration, Time, and Displacement 53 Linking Speed, Acceleration, and Displacement 56 Chapter 4: ollowing Directions: WhichWay Are You Going? 59 Conquering Vectors 59 Waxing Numerical on Vectors 63 Breaking Up Vectors into Components 65 Unmasking the Identities of Vectors 69 Sliding Along on Gravity’s Rainbow: A Velocity Exercise 73 Part 2: May the Forces of Physics Be with You 77 Chapter 5: When Push Comes to Shove: Force 79 Forcing the Issue 79 For His First Trick, Newton’s First Law of Motion 80 Ladies and Gentlemen, Newton’s Second Law of Motion 82 Newton’s Grand Finale: The Third Law of Motion 88 Chapter 6: What a Drag: Inclined Planes and Friction 97 Don’t Let It Get You Down: Dealing with Gravity 97 Leaning Vertical: An Inclined Plane 98 Getting Sticky with Friction 101 Determining How Gravity Affects Airborne Objects 110 Chapter 7: Circling around Circular Motions and Orbits 115 Staying the Course: Uniform Circular Motion 116 Changing Direction: Centripetal Acceleration 117 Pulling Toward the Center: Centripetal Force 118 Negotiating Curves and Banks: Centripetal Force through Turns 120 Getting Angular: Displacement, Velocity, and Acceleration 122 Dropping the Apple: Newton’s Law of Gravitation 124 Looping the Loop: Vertical Circular Motion 129 Part 3: Manifesting the Energy to Work 133 Chapter 8: Getting Some Work out of Physics 135 Work: It Isn’t What You Think 135 Considering Negative Work 138 Getting the Payoff: Kinetic Energy 139 Energy in the Bank: Potential Energy 144 Choose Your Path: Conservative versus Nonconservative Forces 147 Up, Down, and All Around: The Conservation of Mechanical Energy 148 Powering Up: The Rate of Doing Work 151 Chapter 9: Putting Objects in Motion: Momentum and Impulse 153 Looking at the Impact of Impulse 153 Gathering Momentum 155 The Impulse-Momentum Theorem: Relating Impulse and Momentum 156 When Objects Go Bonk: Conserving Momentum 159 When Worlds (or Cars) Collide: Elastic and Inelastic Collisions 164 Chapter 10: Winding Up with Angular Kinetics 169 Going from Linear to Rotational Motion 169 Understanding Tangential Motion 170 Applying Vectors to Rotation 174 Twisting and Shouting: Torque 176 No Wobbling Allowed: Rotational Equilibrium 182 Chapter 11: Round and Round with Rotational Dynamics 189 Rolling Up Newton’s Second Law into Angular Motion 189 Examining Moments of Inertia 192 Wrapping Your Head around Rotational Work and Kinetic Energy 196 Can’t Stop This: Angular Momentum 201 Chapter 12: Springs-n-Things: Simple Harmonic Motion 205 Hooking Up with Hooke’s Law 205 Moving with Simple Harmonic Motion 207 Factoring Energy into Simple Harmonic Motion 218 Swinging with Pendulums 219 Part 4: Laying Down the Laws of Thermodynamics 221 Chapter 13: Turning Up the Heat with Thermodynamics 223 Getting into Hot Water 224 The Heat Is On: Linear Expansion 226 The Heat Continues On: Volume Expansion 229 Going with the Flow (of Heat) 230 Changing Phases: When Temperatures Don’t Change 232 Chapter 14: Here, Take My Coat: Heat Transfer in Solids and Gases 235 Boiling Water: Convection 235 Too Hot to Handle: Conduction 236 Emitting and Absorbing Light: Radiation 240 Crunching Avogadro’s Number 244 Forging the Ideal Gas Law 245 Tracking Ideal Gas Molecules 248 Chapter 15: When Heat and Work Collide: The Laws of Thermodynamics 251 Gaining Thermal Equilibrium: The Zeroth Law of Thermodynamics 251 Conserving Heat and Energy: The First Law of Thermodynamics 252 When Heat Flows: The Second Law of Thermodynamics 262 Going Cold: The Third (and Absolute Last) Law of Thermodynamics 266 Part 5: Getting a Charge out of Electricity and Magnetism 267 Chapter 16: Zapping Away with Static Electricity 269 Plus and Minus: Electron and Proton Charges 269 Push and Pull: Electric Forces 270 Influence at a Distance: Electric Fields 274 Electric Potential: Cranking Up the Voltage 278 Chapter 17: Giving Electrons a Push with Circuits 287 Electrons on the March: Current 287 Giving You Some Resistance: Ohm’s Law 289 Powering Up: Wattage 291 Flowing from One to the Other: Series Circuits 291 Splitting the Current: Parallel Circuits 292 Looping Together Electricity with Kirchoff’s Rules 294 Conquering Capacitors in Parallel and Series Circuits 299 Putting Together Resistors and Capacitors: RC Circuits 301 Chapter 18: Magnetism: More than Attraction 303 Finding the Source of Attraction 304 Forcing a Moving Charge 305 Figuring the Quantitative Size of Magnetic Forces 306 Moving in Orbits: Charged Particles in Magnetic Fields 308 Pushing and Pulling Currents 311 Identifying the Magnetic Field from a Wire 314 Centering on Current Loops 316 Achieving a Uniform Magnetic Field with Solenoids 318 Chapter 19: Keeping the Current Going with Voltage 321 Inducing EMF (Electromagnetic Frequency) 321 Factoring In the Flux with Faraday’s Law 324 Getting the Signs Right with Lenz’s Law 326 Figuring out Inductance 328 Examining Alternating Current Circuits 329 Handling the Triple Threat: RCL Circuits 337 Chapter 20: Shedding Some Light on Mirrors and Lenses 339 All about Mirrors (srorriM tuoba llA) 339 When Light Gets Bendy 340 All Mirrors and No Smoke 343 Seeing Clearly with Lenses 349 Part 6: The Part of Tens 355 Chapter 21: Ten Amazing Insights on Relativity 357 Nature Doesn’t Play Favorites 357 The Speed of Light Is Constant, No Matter How Fast You Go 358 Time Dilates at High Speeds 359 Space Travel Ages You Less 359 Length Contracts at High Speeds 360 E = mc2: The Equivalence of Matter and Energy 361 Matter Plus Antimatter Equals Boom 361 The Sun Is Radiating Away Mass 362 The Speed of Light Is the Ultimate Speed 362 Newton Is Still Right 363 Chapter 22: Ten Wild Physics Theories 365 You Can Measure a Smallest Distance 365 There Might Be a Smallest Time 366 Heisenberg Says You Can’t Be Certain 366 Black Holes Don’t Let Light Out 367 Gravity Curves Space 367 Matter and Antimatter Destroy Each Other 368 Supernovas Are the Most Powerful Explosions 369 The Universe Starts with the Big Bang and Ends with the Gnab Gib 369 Microwave Ovens Are Hot Physics 369 Physicists May Not Have Physical Absolute Measures 370 Glossary 371 Index 377

Does just thinking about the laws of motion make your head spin? Does studying electricity short your circuits? Do the complexities of thermodynamics cool your enthusiasm?

Thanks to this book, you don’t have to be Einstein to understand physics. As you read about Newton’s Laws, Kepler’s Laws, Hooke’s Law, Ohm’s Law, and others, you’ll appreciate the For Dummies law: The easier we make it, the faster people understand it and the more they enjoy it! Whether you’re taking a class, helping kids with homework, or trying to find out how the world works, this book helps you understand basic physics. It covers:

• Measurements, units, and significant figures
• Forces such as displacement, speed, and acceleration
• Vectors and physics notation
• Motion, energy, and waves (sound, light, wave-particle)
• Solids, liquids, and gases
• Thermodynamics
• Electromagnetism
• Relativity
• Atomic and nuclear structures

Steven Holzner, Ph.D. earned his B.S. at MIT and his Ph.D. at Cornell, where he taught Physics 101 and 102 for over 10 years. He livens things up with cool physics facts, real-world examples, and simple experiments that will heighten your enthusiasm for physics and science. The book ends with some out-of-this world physics that will set your mind in motion:

• The possibility of wormholes in space
• The Big Bang
• How the gravitational pull of black holes is too strong for even light to escape

May the Force be with you!

Filled with cool physics facts and real-world examplesThe fun and easy way to get up to speed on the basic concepts of physicsDoes thermodynamics leave you cold? Are you vexed by vectors? Does electromagnetism seem like just a lot of static? Relax! This friendly guide puts the fun back into physics fundamentals.