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1、各种总结范文 TheSweetSpot:AWaveModelofBaseballBatsxxP105AbstractWedeterminethesweetspotonabaseballbat.Wecapturetheessentialphysicsoftheball–batimpactbytakingtheballtobealossyspringandthebattobeanEuler-Bernoullibeam.Toimpart（传授）someintuitionaboutthemodel,webeg
2、inbypresentingarigid-bodymodel.Next,weuseourfullmodeltoreconcile（使一致）variouscorrectandincorrectclaimsaboutthesweetspotfoundintheliterature.Finally,wediscussthesweetspotandtheperformancesofcorkedandaluminumbats,withaparticularemphasisonhoopmodes.Introduct
3、ionAlthoughahittermightexpectamodelofthebat–baseballcollisiontoyieldinsightintohowthebatbreaks,howthebatimpartsspinontheball,howbesttoswingthebat,andsoon,wemodelonlythesweetspot.Thereareatleasttwonotionsofwherethesweetspotshouldbe—animpactlocationontheba
4、tthateither?minimizesthedisforttothehands,or?maximizestheoutgoingvelocityoftheball.Wefocusexclusively(唯一的)ontheseconddefinition.Thevelocityoftheballleavingthebatisdeterminedby?theinitialvelocityandrotationoftheball,?theinitialvelocityandrotationofthebat,
5、?therelativepositionandorientationofthebatandball,and?theforceovertimethatthehitter’shandsappliesonthehandle.Weassumethattheballisnotrotatingandthatitsvelocityatimpactisperpendicularto(垂直于)thelengthofthebat.Weassumethateverythingoursinasingleplane,andwew
6、illarguethatthehands’interaction（交互作用）isnegligible.Intheframeofreference（参照系，坐标，参照标准）ofthecenterofmassofthebat,theinitialconditionsarepletelyspecified（说明）by?theangularvelocity（角速度）ofthebat,?thevelocityoftheball,and?thepositionofimpactalongthebat.Thelocat
7、ionofthesweetspotdependsnotonjustthebatalonebutalsoonthepitchandontheswing.Thesimplestmodelforthephysicsinvolvedhasthesweetspotatthecenterofpercussion[Brody1986],theimpactlocationthatminimizesdis-forttothehand.Themodelassumestheballtobearigidbodyforwhich
8、thereareconjugatepoints（共轭点）:Animpactatonewillexactlybalancetheangularrecoilandlinearrecoilattheother.Bygrippingatoneandimpactingattheother(thecenterofpercussion),thehandsexperienceminimalshockandtheballexitswithhighveloci
