The new Ninth Edition of Halliday, Resnick and Walker's Principles of Physics has been strategically revised to focus on engaging students, supporting critical thinking and moving students to the next level of physics understanding. Key to the Ninth Edition's support for critical thinking and development of understanding physics concepts is Jearl Walker's modern voice. Jearl Walker is both an active teacher, who understands the challenges faced in today's classroom, and a world renowned communicator of science to the general public. His Flying Circus of Physics is a cult classic among physics students and instructors and material from this book is integrated throughout the Ninth Edition to catch students' attention, engage them, and encourage them to solve the underlying real world physics phenomenon and concepts, before they begin the more quantitative portion of the content or problem. Integration of The Flying Circus of Physics. Material from The Flying Circus is incorporated into the chapter opener puzzlers, Sample Problems, text examples and end-of-chapter problems to make the subject more interesting and engaging and to show students that the world around them can be examined and understood using the fundamental principles of physics. Links to The Flying Circus material are identified throughout the text with a biplane icon. Checkpoints offer stopping points so students can check their understanding of a question with some reasoning based on the narrative or sample problem they just read. Sample problems are chosen to demonstrate how problems can be solved with reasoned solutions rather than quick and simplistic plugging of numbers into an equation with no regard for what the equation means. Key Ideas in the sample problems focus a student on the basic concepts at the root of the solution to a problem.

**1 MEASUREMENT.**1-1 What Is Physics?

1-2 Measuring Things**.**

1-3 The International System of Units**.**

1-4 Changing Units**.**

1-5 Length**.**

1-6 Time**.**

1-7 Mass**.**

REVIEW & SUMMARY.

PROBLEMS**.**

**2 MOTION ALONG A STRAIGHT LINE.**

2-1 What Is Physics?

2-2 Motion**.**

2-3 Position and Displacement**.**

2-4 Average Velocity and Average Speed**.**

2-5 Instantaneous Velocity and Speed**.**

2-6 Acceleration**.**

2-7 Constant Acceleration: A Special Case**.**

2-8 Another Look at Constant Acceleration**.**

2-9 Free-Fall Acceleration**.**

2-10 Graphical Integration in Motion Analysis**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**3 VECTORS.**

3-1 What Is Physics?

3-2 Vectors and Scalars**.**

3-3 Adding Vectors Geometrically**.**

3-4 Components of Vectors**.**

3-5 Unit Vectors**.**

3-6 Adding Vectors by Components**.**

3-7 Vectors and the Laws of Physics**.**

3-8 Multiplying Vectors**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**4 MOTION IN TWO AND THREE DIMENSIONS.**

4-1 What Is Physics?

4-2 Position and Displacement**.**

4-3 Average Velocity and Instantaneous Velocity**.**

4-4 Average Acceleration and Instantaneous Acceleration**.**

4-5 Projectile Motion**.**

4-6 Projectile Motion Analyzed**.**

4-7 Uniform Circular Motion**.**

4-8 Relative Motion in One Dimension**.**

4-9 Relative Motion in Two Dimensions**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**5 FORCE AND MOTION—I.**

5-1 What Is Physics?

5-2 Newtonian Mechanics**.**

5-3 Newton’s First Law**.**

5-4 Force**.**

5-5 Mass**.**

5-6 Newton’s Second Law**.**

5-7 Some Particular Forces**.**

5-8 Newton’s Third Law**.**

5-9 Applying Newton’s Laws**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**6 FORCE AND MOTION—II.**

6-1 What Is Physics?

6-2 Friction**.**

6-3 Properties of Friction**.**

6-4 The Drag Force and Terminal Speed**.**

6-5 Uniform Circular Motion**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**7 KINETIC ENERGY AND WORK.**

7-1 What Is Physics?

7-2 What Is Energy?

7-3 Kinetic Energy**.**

7-4 Work**.**

7-5 Work and Kinetic Energy**.**

7-6 Work Done by the Gravitational Force**.**

7-7 Work Done by a Spring Force**.**

7-8 Work Done by a General Variable Force**.**

7-9 Power**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**8 POTENTIAL ENERGY AND CONSERVATION OF ENERGY.**

8-1 What Is Physics?

8-2 Work and Potential Energy**.**

8-3 Path Independence of Conservative Forces**.**

8-4 Determining Potential Energy Values**.**

8-5 Conservation of Mechanical Energy**.**

8-6 Reading a Potential Energy Curve**.**

8-7 Work Done on a System by an External Force**.**

8-8 Conservation of Energy**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**9 CENTER OF MASS AND LINEAR MOMENTUM.**

9-1 What Is Physics?

9-2 The Center of Mass**.**

9-3 Newton’s Second Law for a System of Particles**.**

9-4 Linear Momentum**.**

9-5 The Linear Momentum of a System of Particles**.**

9-6 Collision and Impulse**.**

9-7 Conservation of Linear Momentum**.**

9-8 Momentum and Kinetic Energy in Collisions**.**

9-9 Inelastic Collisions in One Dimension**.**

9-10 Elastic Collisions in One Dimension**.**

9-11 Collisions in Two Dimensions**.**

9-12 Systems with Varying Mass: A Rocket**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**10 ROTATION.**

10-1 What Is Physics?

10-2 The Rotational Variables**.**

10-3 Are Angular Quantities Vectors?

10-4 Rotation with Constant Angular Acceleration**.**

10-5 Relating the Linear and Angular Variables**.**

10-6 Kinetic Energy of Rotation**.**

10-7 Calculating the Rotational Inertia**.**

10-8 Torque**.**

10-9 Newton’s Second Law for Rotation**.**

10-10 Work and Rotational Kinetic Energy**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**11 ROLLING, TORQUE, AND ANGULAR MOMENTUM.**

11-1 What Is Physics?

11-2 Rolling as Translation and Rotation Combined**.**

11-3 The Kinetic Energy of Rolling**.**

11-4 The Forces of Rolling**.**

11-5 The Yo-Yo**.**

11-6 Torque Revisited**.**

11-7 Angular Momentum**.**

11-8 Newton’s Second Law in Angular Form**.**

11-9 The Angular Momentum of a System of Particles**.**

11-10 The Angular Momentum of a Rigid Body Rotating About a Fixed Axis**.**

11-11 Conservation of Angular Momentum**.**

11-12 Precession of a Gyroscope**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**12 EQUILIBRIUM AND ELASTICITY.**

12-1 What Is Physics?

12-2 Equilibrium**.**

12-3 The Requirements of Equilibrium**.**

12-4 The Center of Gravity**.**

12-5 Some Examples of Static Equilibrium**.**

12-6 Indeterminate Structures**.**

12-7 Elasticity**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**13 GRAVITATION.**

13-1 What Is Physics?

13-2 Newton’s Law of Gravitation**.**

13-3 Gravitation and the Principle of Superposition**.**

13-4 Gravitation Near Earth’s Surface**.**

13-5 Gravitation Inside Earth**.**

13-6 Gravitational Potential Energy**.**

13-7 Planets and Satellites: Kepler’s Laws**.**

13-8 Satellites: Orbits and Energy**.**

13-9 Einstein and Gravitation**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**14 FLUIDS.**

14-1 What Is Physics?

14-2 What Is a Fluid?

14-3 Density and Pressure**.**

14-4 Fluids at Rest**.**

14-5 Measuring Pressure**.**

14-6 Pascal’s Principle**.**

14-7 Archimedes’ Principle**.**

14-8 Ideal Fluids in Motion**.**

14-9 The Equation of Continuity**.**

14-10 Bernoulli’s Equation**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**15 OSCILLATIONS.**

15-1 What Is Physics?

15-2 Simple Harmonic Motion**.**

15-3 The Force Law for Simple Harmonic Motion**.**

15-4 Energy in Simple Harmonic Motion**.**

15-5 An Angular Simple Harmonic Oscillator**.**

15-6 Pendulums**.**

15-7 Simple Harmonic Motion and Uniform Circular Motion**.**

15-8 Damped Simple Harmonic Motion**.**

15-9 Forced Oscillations and Resonance**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**16 WAVES—I.**

16-1 What Is Physics?

16-2 Types of Waves**.**

16-3 Transverse and Longitudinal Waves**.**

16-4 Wavelength and Frequency**.**

16-5 The Speed of a Traveling Wave**.**

16-6 Wave Speed on a Stretched String**.**

16-7 Energy and Power of a Wave Traveling Along a String**.**

16-8 The Wave Equation**.**

16-9 The Principle of Superposition for Waves**.**

16-10 Interference of Waves**.**

16-11 Phasors**.**

16-12 Standing Waves**.**

16-13 Standing Waves and Resonance**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**17 WAVES—II.**

17-1 What Is Physics?

17-2 Sound Waves**.**

17-3 The Speed of Sound**.**

17-4 Traveling Sound Waves**.**

17-5 Interference**.**

17-6 Intensity and Sound Level**.**

17-7 Sources of Musical Sound**.**

17-8 Beats**.**

17-9 The Doppler Effect**.**

17-10 Supersonic Speeds, Shock Waves**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**18 TEMPERATURE, HEAT, AND THE FIRST LAW OF THERMODYNAMICS.**

18-1 What Is Physics?

18-2 Temperature**.**

18-3 The Zeroth Law of Thermodynamics**.**

18-4 Measuring Temperature**.**

18-5 The Celsius and Fahrenheit Scales**.**

18-6 Thermal Expansion**.**

18-7 Temperature and Heat**.**

18-8 The Absorption of Heat by Solids and Liquids**.**

18-9 A Closer Look at Heat and Work**.**

18-10 The First Law of Thermodynamics**.**

18-11 Some Special Cases of the First Law of Thermodynamics**.**

18-12 Heat Transfer Mechanisms**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**19 THE KINETIC THEORY OF GASES.**

19-1 What Is Physics?

19-2 Avogadro’s Number**.**

19-3 Ideal Gases**.**

19-4 Pressure, Temperature, and RMS Speed**.**

19-5 Translational Kinetic Energy**.**

19-6 Mean Free Path**.**

19-7 The Distribution of Molecular Speeds**.**

19-8 The Molar Specific Heats of an Ideal Gas**.**

19-9 Degrees of Freedom and Molar Specific Heats**.**

19-10 A Hint of Quantum Theory**.**

19-11 The Adiabatic Expansion of an Ideal Gas**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**20 ENTROPY AND THE SECOND LAW OF THERMODYNAMICS.**

20-1 What Is Physics?

20-2 Irreversible Processes and Entropy**.**

20-3 Change in Entropy**.**

20-4 The Second Law of Thermodynamics**.**

20-5 Entropy in the Real World: Engines**.**

20-6 Entropy in the Real World: Refrigerators**.**

20-7 The Efficiencies of Real Engines**.**

20-8 A Statistical View of Entropy**.**

REVIEW & SUMMARY.

QUESTIONS.

PROBLEMS**.**

**APPENDICES.**

A The International System of Units (SI)**.**

B Some Fundamental Constants of Physics**.**

C Some Astronomical Data**.**

D Conversion Factors**.**

E Mathematical Formulas**.**

F Properties of the Elements**.**

G Periodic Table of the Elements**.**

ANSWERS to Checkpoints and Odd-Numbered Questions and Problems**.**

INDEX**.**