[eBook Code] Physics Essentials For Dummies (eBook Code, 1st)

Introduction 1

About This Book 1

Conventions Used in This Book 2

Foolish Assumptions 2

Icons Used in This Book 3

Where to Go from Here 3

Chapter 1: Viewing the World through the Lens of Physics 5

Figuring Out What Physics is About 5

Paying Attention to Objects in Motion 6

Getting Energized 7

Moving as Fast as You Can: Special Relativity 8

Measuring Your World 9

Keeping physical units straight 9

Converting between units of measurement 10

Nixing some zeros with scientific notation 11

Knowing which digits are significant 12

Chapter 2: Taking Vectors Step by Step 15

Getting a Grip on Vectors 15

Looking for direction and magnitude 16

Adding vectors 17

Subtracting vectors 18

Waxing Numerical on Vectors 19

Working with Vector Components 20

Using magnitudes and angles to find vector components 20

Using vector components to find magnitudes and angles 22

Chapter 3: Going the Distance with Speed and Acceleration 25

From Here to There: Dissecting Displacement 26

Examining axes 27

Measuring speed 28

The Fast Track to Understanding Speed and Velocity 29

How fast am I right now? Instantaneous speed 30

Staying steady: Uniform speed 30

Changing your speed: Nonuniform motion 30

Doing some calculations: Average speed 31

Contrasting average speed and instantaneous speed 31

Speeding Up (or Slowing Down): Acceleration 33

Defining our terms 33

Recognizing positive and negative acceleration 33

Looking at average and instantaneous acceleration 34

Accounting for uniform and nonuniform acceleration 35

Bringing Acceleration, Time, and Displacement Together 35

Locating not-so-distant relations 36

Equating more speedy scenarios 37

Putting Speed, Acceleration, and Displacement Together 38

Chapter 4: Studying Circular Motions 41

Understanding Uniform Circular Motion 42

Creating Centripetal Acceleration 43

Seeing how centripetal acceleration controls velocity 44

Calculating centripetal acceleration 44

Finding Angular Equivalents for Linear Equations 45

Chapter 5: Push-Ups and Pull-Ups: Exercises in Force 49

Reckoning with Force 49

Objects at Rest and in Motion: Newton’s First Law 50

Calculating Net Force: Newton’s Second Law 51

Gathering net forces 52

Just relax: Dealing with tension 56

A balancing act: Finding equilibrium 57

Equal and Opposite Reactions: Newton’s Third Law 60

Chapter 6: Falling Slowly: Gravity and Friction 63

Dropping the Apple: Newton’s Law of Gravitation 63

Down to Earth: Dealing with Gravity 65

Leaning Vertically with Inclined Planes 66

Facing Friction 68

Figuring out the normal force 69

Finding the coefficient of friction 69

Bringing static and kinetic friction into the mix 71

Dealing with uphill friction 73

Chapter 7: Putting Physics to Work 77

Wrapping Your Mind around Work 77

Pushing your weight 78

Taking a drag 79

Working Backward: Negative Work 80

Working Up a Sweat: Kinetic Energy 81

Breaking down the kinetic energy equation 82

Using the kinetic energy equation 83

Calculating kinetic energy by using net force 85

Saving Up: Potential Energy 87

Working against gravity 87

Converting potential energy into kinetic energy 88

Pitting Conservative against Nonconservative Forces 89

No Work Required: The Conservation of Mechanical Energy 91

A Powerful Idea: The Rate of Doing Work 92

Chapter 8: Moving Objects with Impulse and Momentum 95

Feeling a Sudden Urge to Do Physics: Impulse 95

Mastering Momentum 97

Connecting Impulse and Momentum 98

Taking impulse and momentum to the pool hall 99

Getting impulsive in the rain 100

Watching Objects Go Bonk: The Conservation of Momentum 101

Measuring Firing Velocity 103

Examining Elastic and Inelastic Collisions 105

Flying apart: Elastic collisions 105

Sticking together: Inelastic collisions 105

Colliding along a line 106

Colliding in two dimensions 107

Chapter 9: Navigating the Twists and Turns of Angular Kinetics 111

Changing Gears (and Equations) from Linear to Rotational Motion 112

Tackling Tangential Motion 112

Calculating tangential speed 113

Figuring out tangential acceleration 114

Looking at centripetal acceleration 115

Applying Vectors to Rotation 116

Analyzing angular velocity 116

Working out angular acceleration 117

Doing the Twist with Torque 119

Walking through the torque equation 120

Mastering lever arms 122

Identifying the torque generated 122

Realizing that torque is a vector 124

No Spin, Just the Unbiased Truth: Rotational Equilibrium 125

Chapter 10: Taking a Spin with Rotational Dynamics 127

Converting Newton’s Second Law into Angular Motion 127

Moving from tangential to angular acceleration 129

Bringing the moment of inertia into play 129

Finding Moments of Inertia for Standard Shapes 131

Doing Rotational Work and Producing Kinetic Energy 132

Making the transition to rotational work 133

Solving for rotational kinetic energy 134

Going Round and Round with Angular Momentum 136

Chapter 11: There and Back Again: Simple Harmonic Motion 139

Homing in on Hooke’s Law 139

Staying within the elastic limit 140

Exerting a restoring force 141

Déjà Vu All Over Again: Simple Harmonic Motion 142

Browsing the basics of simple harmonic motion 142

Exploring some complexities of simple harmonic motion 144

Finding angular frequencies of masses on springs 151

Examining Energy in Simple Harmonic Motion 154

Going for a Swing with Pendulums 155

Chapter 12: Ten Marvels of Relativity 159

Nature Doesn’t Play Favorites 159

The Speed of Light is Constant 160

Time Contracts at High Speeds 161

Space Travel Slows Down Aging 162

Length Shortens at High Speeds 162

Matter and Energy are Equivalent: E = mc² 163

Matter + Antimatter Equals Boom 164

The Sun is Losing Mass 164

You Can’t Surpass the Speed of Light 164

Newton Was Right 165

Index 167