PAIREDREADMachinestoPushandPullInformationalTextbyBeverlyHarrisSTRATEGIES&SKILLSAPhotographyCredit:CoverImageSource/GaelConrad/CORBIS**Thetotalwordcountisbasedonwordsintherunningtextandheadingsonly.Numeralsandwordsincaptions,labels,diagrams,charts,andsidebarsarenotincluded.Wordcount:670**ComprehensionStrategy:RereadSkill:Author’sPurposePhonicsLonga:a,ai,ay,ea,ei,eigh,eyVocabularyStrategySimilesVocabularyamazing,force,measure,objects,proved,speed,true,weightContentStandardsSciencePhysicalScienceCopyright©TheMcGraw-HillCompanies,Inc.Allrightsreserved.Nopartofthispublicationmaybereproducedordistributedinanyformorbyanymeans,orstoredinadatabaseorretrievalsystem,withoutthepriorwrittenconsentofTheMcGraw-HillCompanies,Inc.,including,butnotlimitedto,networkstorageortransmission,orbroadcastfordistancelearning.Sendallinquiriesto:McGraw-HillEducationTwoPennPlazaNewYork,NewYork10121ISBN:978-0-02-119031-7MHID:0-02-119031-3PrintedintheUnitedStates.12345678DOC171615141312PAIREDREADChapter1Forces............................2Chapter2FrictionatthePark................6Chapter3FrictionandStopping..............10Chapter4LessFriction......................13RespondtoReading...............15MachinestoPushandPull..16Glossary/Index....................19FocusonScience...........20EssentialQuestionHowdotheearth’sforcesaffectus?GenreInformationalTextbyBeverlyHarrisMichaelNewman/PhotoEditAforcepushesorpulls.Forcesaffecthowobjectsmove.Youseeforcesworkingallthetime.Whenyoupushsomeoneonaswing,youuseaforce.CHAPTER12AndersonRoss/BlendImages/CORBISAdoorswingsopenwhenyoupushit.Agrocerycartmovesifyoupushit.Adoorcloseswhenyoupullitshut.Adraweropensifyoupullit.Pullingisaforcetoo.3JuiceImages/CORBISGravityisaforce.Itpullsobjects.OnEarth,gravitypullsobjectstowardtheground.Gravityevenpullsyou!Youcantestgravity.Dropapencil.Whathappened?Itfell.Why?Gravitypulleditdown.It’strue!Gravityworks.Youprovedit.Gravitymakesthetomatoespushdownonthescale.4RobSchusterFrictionisanotherforce.Itaffectshowthingsmove.Itisd...
