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Science/Physicsg Easier!Making Everythin 2nd EditionThe fast and easy wayto get up to speed on physics Get into motion — start your journey with a look at acceleration,velocity, and displacement, which is a great way to understandhow physics works May the force be with you — get the 411 on Newton’s laws andeasily grasp equal and opposite forces, inertia and mass, friction,equilibrium, and much more Make physics work — discover the ins and outs of turning energyinto work, conserving mechanical energy, and seeing how rotationalmotion makes the world go ‘roundIscisyPh How to measure displacement,speed, velocity, and acceleration Math fundamentals and systemsof measurement you need to know Plain-English explanations ofNewton’s laws The lowdown on gravity, inclinedplanes, and friction A look at centripetal acceleration,momentum and impulse, andangular kinetics The scoop on fluids, flow,and pressurePhysics IIf just thinking about the laws of physics makes your headspin, this hands-on, friendly guide gets you out of theblack hole and sheds light on this often-intimidatingsubject. Tracking to a typical Physics I course, it teachesyou the basic principles and formulas in a clear and concisemanner, proving that you don’t have to be Einstein tounderstand physics!Open the book and find: The laws of thermodynamics Turn up the heat with thermodynamics — find out everythingyou need to know about the physics of heat, temperature, andthe ideal gas laws you’ll encounter in your studiesLearn to: Get up to speed on the basicconcepts of physicsGo to Dummies.com for videos, step-by-step examples,how-to articles, or to shop! Grasp formulas in a clear andconcise manner Explore the newest discoveriesin the field 19.99 US / 23.99 CN / 14.99 UKSteven Holzner, PhD is a former contributing editor at PC Magazineand has been on the faculty of both MIT and Cornell University. He isthe author of Physics II For Dummies, Physics Essentials For Dummies, andQuantum Physics For Dummies.ISBN 978-0-470-90324-7Steven Holzner, PhDHolznerEducator and author2nd Edition

Get More and Do More at Dummies.com Start with FREE Cheat SheetsCheat Sheets include Checklists Charts Common Instructions And Other Good Stuff!To access the Cheat Sheet created specifically for this book, go towww.dummies.com/cheatsheet/physics1sppAeliMobGet Smart at Dummies.comDummies.com makes your life easier with 1,000sof answers on everything from removing wallpaperto using the latest version of Windows.Check out our Videos Illustrated Articles Step-by-Step InstructionsPlus, each month you can win valuable prizes by enteringour Dummies.com sweepstakes. *Want a weekly dose of Dummies? Sign up for Newsletters on Digital Photography Microsoft Windows & Office Personal Finance & Investing Health & Wellness Computing, iPods & Cell Phones eBay Internet Food, Home & GardenFind out “HOW” at Dummies.com*Sweepstakes not currently available in all countries; visit Dummies.com for official rules.There’s a Dummies App for This and ThatWith more than 200 million books in print and over 1,600 uniquetitles, Dummies is a global leader in how-to information. Nowyou can get the same great Dummies information in an App. Withtopics such as Wine, Spanish, Digital Photography, Certification,and more, you’ll have instant access to the topics you need toknow in a format you can trust.To get information on all our Dummies apps, visit the following:www.Dummies.com/go/mobile from your computer.www.Dummies.com/go/iphone/apps from your phone.

Physics IFORDUMmIES‰2NDEDITION

Physics IFORDUMmIES‰2NDEDITIONby Steven Holzner, PhD

Physics I For Dummies , 2nd EditionPublished byWiley Publishing, Inc.111 River St.Hoboken, NJ 07030-5774www.wiley.comCopyright 2011 by Wiley Publishing, Inc., Indianapolis, IndianaPublished by Wiley Publishing, Inc., Indianapolis, IndianaPublished simultaneously in CanadaNo part of this publication may be reproduced, stored in a retrieval system or transmitted in any form orby any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permittedunder Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior writtenpermission of the Publisher, or authorization through payment of the appropriate per-copy fee to theCopyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600.Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley& Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions.Trademarks: Wiley, the Wiley Publishing logo, For Dummies, the Dummies Man logo, A Reference for theRest of Us!, The Dummies Way, Dummies Daily, The Fun and Easy Way, Dummies.com, Making EverythingEasier, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries, and may not be used without written permission.All other trademarks are the property of their respective owners. Wiley Publishing, Inc., is not associatedwith any product or vendor mentioned in this book.LIMIT OF LIABILITY/DISCLAIMER OF WARRANTY: THE PUBLISHER AND THE AUTHOR MAKE NOREPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OFTHE CONTENTS OF THIS WORK AND SPECIFICALLY DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE. NO WARRANTY MAY BECREATED OR EXTENDED BY SALES OR PROMOTIONAL MATERIALS. THE ADVICE AND STRATEGIESCONTAINED HEREIN MAY NOT BE SUITABLE FOR EVERY SITUATION. THIS WORK IS SOLD WITH THEUNDERSTANDING THAT THE PUBLISHER IS NOT ENGAGED IN RENDERING LEGAL, ACCOUNTING, OROTHER PROFESSIONAL SERVICES. IF PROFESSIONAL ASSISTANCE IS REQUIRED, THE SERVICES OFA COMPETENT PROFESSIONAL PERSON SHOULD BE SOUGHT. NEITHER THE PUBLISHER NOR THEAUTHOR SHALL BE LIABLE FOR DAMAGES ARISING HEREFROM. THE FACT THAT AN ORGANIZATION OR WEBSITE IS REFERRED TO IN THIS WORK AS A CITATION AND/OR A POTENTIAL SOURCEOF FURTHER INFORMATION DOES NOT MEAN THAT THE AUTHOR OR THE PUBLISHER ENDORSESTHE INFORMATION THE ORGANIZATION OR WEBSITE MAY PROVIDE OR RECOMMENDATIONS ITMAY MAKE. FURTHER, READERS SHOULD BE AWARE THAT INTERNET WEBSITES LISTED IN THISWORK MAY HAVE CHANGED OR DISAPPEARED BETWEEN WHEN THIS WORK WAS WRITTEN ANDWHEN IT IS READ.For general information on our other products and services, please contact our Customer CareDepartment within the U.S. at 877-762-2974, outside the U.S. at 317-572-3993, or fax 317-572-4002.For technical support, please visit www.wiley.com/techsupport.Wiley also publishes its books in a variety of electronic formats. Some content that appears in print maynot be available in electronic books.Library of Congress Control Number: 2011926317ISBN: 978-0-470-90324-7Manufactured in the United States of America10 9 8 7 6 5 4 3 2 1

About the AuthorSteven Holzner is an award-winning author of 94 books, which have soldmore than 2 million copies and have been translated into 18 languages. Heserved on the Physics faculty at Cornell University for more than a decade,teaching both Physics 101 and Physics 102. Dr. Holzner received his PhD inphysics from Cornell and performed his undergrad work at MIT, where hehas also served as a faculty member.

DedicationTo Nancy.Author’s AcknowledgmentsAny book such as this one is the work of many people besides the author. I’dlike to thank my acquisitions editor, Stacy Kennedy, and everyone else whohad a hand in the book’s contents, including Tracy Barr, Danielle Voirol, JoelBryan, Eric Hedin, and Neil Clark. Thank you, everyone.

Publisher’s AcknowledgmentsWe’re proud of this book; please send us your comments at http://dummies.custhelp.com. Forother comments, please contact our Customer Care Department within the U.S. at 877-762-2974, outside the U.S. at 317-572-3993, or fax 317-572-4002.Some of the people who helped bring this book to market include the following:Acquisitions, Editorial, and MediaDevelopmentEditors: Tracy Barr, Danielle VoirolComposition ServicesProject Coordinator: Katherine CrockerAcquisitions Editor: Stacy KennedyLayout and Graphics: Corrie Socolovitch,Christin Swinford, Laura WesthuisAssistant Editor: David LuttonProofreaders: Laura Albert, Laura BowmanEditorial Program Coordinator: Joe NiesenIndexer: Infodex Indexing Services, Inc.Technical Editors: Joel Bryan, PhD;Eric Hedin, PhDSpecial HelpNeil Clark, Krista FanningEditorial Managers: Jennifer Erhlich, SeniorEditorial Manager; Carmen Krikorian,Editorial Supervisor and Reprint EditorEditorial Assistants: Jennette ElNaggar,Rachelle S. AmickCover Photos: iStockphoto.com / Marco MartinsCartoons: Rich Tennant (www.the5thwave.com)Publishing and Editorial for Consumer DummiesDiane Graves Steele, Vice President and Publisher, Consumer DummiesKristin Ferguson-Wagstaffe, Product Development Director, Consumer DummiesEnsley Eikenburg, Associate Publisher, TravelKelly Regan, Editorial Director, TravelPublishing for Technology DummiesAndy Cummings, Vice President and Publisher, Dummies Technology/General UserComposition ServicesDebbie Stailey, Director of Composition Services

Contents at a GlanceIntroduction . 1Part I: Putting Physics into Motion . 5Chapter 1: Using Physics to Understand Your World . 7Chapter 2: Reviewing Physics Measurement and Math Fundamentals . 15Chapter 3: Exploring the Need for Speed . 27Chapter 4: Following Directions: Motion in Two Dimensions . 51Part II: May the Forces of Physics Be with You . 77Chapter 5: When Push Comes to Shove: Force . 79Chapter 6: Getting Down with Gravity, Inclined Planes, and Friction. 99Chapter 7: Circling around Rotational Motion and Orbits . 117Chapter 8: Go with the Flow: Looking at Pressure in Fluids . 137Part III: Manifesting the Energy to Work . 161Chapter 9: Getting Some Work Out of Physics. 163Chapter 10: Putting Objects in Motion: Momentum and Impulse . 187Chapter 11: Winding Up with Angular Kinetics. 207Chapter 12: Round and Round with Rotational Dynamics . 233Chapter 13: Springs ’n’ Things: Simple Harmonic Motion . 251Part IV: Laying Down the Laws of Thermodynamics . 269Chapter 14: Turning Up the Heat with Thermodynamics. 271Chapter 15: Here, Take My Coat: How Heat Is Transferred. 287Chapter 16: In the Best of All Possible Worlds: The Ideal Gas Law . 303Chapter 17: Heat and Work: The Laws of Thermodynamics . 315Part V: The Part of Tens . 345Chapter 18: Ten Physics Heroes . 347Chapter 19: Ten Wild Physics Theories . 353Glossary . 361Index . 367

Table of ContentsIntroduction . 1About This Book . 1Conventions Used in This Book . 1What You’re Not to Read . 2Foolish Assumptions . 2How This Book Is Organized . 2Part I: Putting Physics into Motion . 2Part II: May the Forces of Physics Be with You . 3Part III: Manifesting the Energy to Work . 3Part IV: Laying Down the Laws of Thermodynamics . 3Part V: The Part of Tens . 3Icons Used in This Book . 4Where to Go from Here . 4Part I: Putting Physics into Motion . 5Chapter 1: Using Physics to Understand Your World . . . . . . . . . . . . . . .7What Physics Is All About . 7Observing the world . 8Making predictions . 8Reaping the rewards. 9Observing Objects in Motion . 10Measuring speed, direction, velocity, and acceleration . 10Round and round: Rotational motion. 11Springs and pendulums: Simple harmonic motion. 11When Push Comes to Shove: Forces . 12Absorbing the energy around you . 13That’s heavy: Pressures in fluids . 13Feeling Hot but Not Bothered: Thermodynamics . 14