




已阅读5页,还剩83页未读, 继续免费阅读
版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领
文档简介
SORACLASSESIVSEZABTEACHERSANNARITASBARDELLAEMILIANAMANCINIVINCENZORECCHIAPOWERPOINTPRESENTATIONREALIZEDBYLORENZOCORSETTICLASSVACRISTIANODIAMANTICLASSVAFRANCESCODORAZIOCLASSVALICEOSCIENTIFICOSTATALE“LEONARDODAVINCI“SORAITALYCOMENIUS13“ENCOHANENERGYINTHECONSUMERSHANDS”20052008TEACHERSANNARITASBARDELLAEMILIANAMANCINIVINCENZORECCHIACLASSESIVSEZABLICEOSCIENTIFICOSTATALE“LEONARDODAVINCI“SORAITALYCOMENIUS13“ENCOHANENERGYINTHECONSUMERSHANDS“20052008“ENCOHAN”PROJECTMEETINGINHUNGHERY6THNOVEMBER/11THNOVEMBER2006TEACHERSEMILIANAMANCINIVINCENZORECCHIA“ENCOHAN”PROJECTMEETINGINPOLAND25THMARCH/1STAPRIL2007TEACHERSANNARITASBARDELLACOORDINATORVINCENZORECCHIASTUDENTSFRANCESCAFORNARICLASSIVAMARTINALIBURDICLASSIVALUCALOMBARDICLASSIVALUIGIRECCHIACLASSIVACHIARAIAFRATECLASSIVBALESSIAPANTANOCLASSIVBILARIAURBANICLASSIVBSILVIAVENDITTICLASSIVBDRINKINGBIRDDRINKINGBIRDSARETHERMODINAMICALLYPOWEREDTOYHEATENGINESTHATMIMICKTHEMOTIONSOFABIRDDRINKINGFROMAFOUNTAINOROTHERWATERSOURCETHEYAREALSOKNOWNASHAPPY,DIPPY,DIPPING,TIPPY,TIPPING,SIPPY,SIPPING,DIPDIPORDUNKINGBIRDSCONSTRUCTIONANDMATERIALSADRINKINGBIRDCONSISTSOFTWOGLASSBULBS,JOINEDBYATUBETHEBIRDSNECKTHETUBEEXTENDSNEARLYALLTHEWAYINTOTHEBOTTOMBULBBUTDOESNOTEXTENDINTOTHETOPTHESPACEINSIDEISTYPICALLYFILLEDWITHCOLOUREDDICHLOROMETHANEALSOKNOWNASMETHYLENECHLORIDEAIRISREMOVEDFROMTHEAPPARATUS,SOTHESPACEINSIDETHEBODYISFILLEDBYDICHLOROMETHANEVAPOURTHEUPPERBULBHASA“BEAK“ATTACHED,WHICHALONGWITHTHEHEAD,ISCOVEREDINAFELTLIKEMATERIALTHEBIRDISTYPICALLYDECORATEDWITHPAPEREYES,ABLUETOPHATPLASTICANDASINGLEGREENTAILFEATHERTHEWHOLESETUPISPIVOTEDONAVARIABLEPOINTONTHENECKTHEDRINKINGBIRDILLUSTRATESTHECONVERSIONOFTHERMALENERGYINTOMECHANICALENERGYTHEHEADOFTHEBIRDISCOATEDWITHAFUZZYMATERIAL,ANDISINITIALLYSOAKEDINWATERSOTHATITWILLBEGINTOCOOLBYEVAPORATIONTHISPROVIDESTHETEMPERATUREDIFFERENCEFROMHEADTOTAILNECESSARYTORUNTHEHEATENGINEASTHEHEADCOOLS,THECOLOREDFLUIDISOBSERVEDTORISEUPFROMTHEBOTTOMOFTHEBIRDTHROUGHTHENECK,GRADUALLYSHIFTINGTHECENTEROFGRAVITYOFTHEBIRDTOWARDITSHEADTHEBIRDBENDSATTHEHIPSANDDIPSITSBILLINTOAGLASSOFWATERTHUSKEEPINGTHEHEADWETANDCOOLERTHANTHETAILASTHEFLUIDCONTINUESTORISEINTOTHEHEAD,THEFLUIDLEVELINTHEBOTTOMOFTHEBIRDEVENTUALLYDROPSBELOWTHEENDOFTHECONNECTINGTUBETHISALLOWSVAPORTOBEPULLEDUPTHROUGHTHENECKTOEQUILIBRATETHEPRESSURETHEFLUIDRUNSBACKDOWNINTOTHEBOTTOMOFTHEBIRD,THEBIRDSTANDSUPAGAIN,ANDTHECYCLEREPEATSINDEFINITELYTHEDRINKINGBIRDISBASICALLYAHEATENGINETHATEXPLOITSATEMPERATUREDIFFERENTIALTOCONVERTHEATENERGYTOKINETICENERGYANDPERFORMMECHANICALWORKLIKEALLHEATENGINES,THEDRINKINGBIRDWORKSTHROUGHATHERMODYNAMICCYCLETHEINITIALSTATEOFTHESYSTEMISABIRDWITHAWETHEADORIENTEDVERTICALLYWITHANINITIALOSCILLATIONONITSPIVOTDRINKINGBIRDDRINKINGBIRDTHECYCLEOPERATESASFOLLOWSTHEWATEREVAPORATESFROMTHEHEADEVAPORATIONLOWERSTHETEMPERATUREOFTHEGLASSHEADTHETEMPERATUREDROPCAUSESSOMEOFTHEDICHLOROMETHANEVAPORINTHEHEADTOCONDENSETHELOWERTEMPERATUREANDCONDENSATIONTOGETHERCAUSETHEPRESSURETODROPINTHEHEADIDEALGASLAWTHEPRESSUREDIFFERENTIALBETWEENTHEHEADANDBASECAUSESTHELIQUIDTOBEPUSHEDUPFROMTHEBASEASLIQUIDFLOWSINTOTHEHEAD,THEBIRDBECOMESTOPHEAVYANDTIPSOVERDURINGITSOSCILLATIONSWHENTHEBIRDTIPSOVER,THEBOTTOMENDOFTHENECKTUBERISESABOVETHESURFACEOFTHELIQUIDABUBBLEOFVAPORRISESUPTHETUBETHROUGHTHISGAP,DISPLACINGLIQUIDASITGOESLIQUIDFLOWSBACKTOTHEBOTTOMBULB,ANDVAPORPRESSUREEQUALIZESBETWEENTHETOPANDBOTTOMBULBSTHEWEIGHTOFTHELIQUIDINTHEBOTTOMBULBRESTORESTHEBIRDTOITSVERTICALPOSITIONIFAGLASSOFWATERISPLACEDSOTHATTHEBEAKDIPSINTOITONITSDESCENT,THEBIRDWILLCONTINUETOABSORBWATERANDTHECYCLEWILLCONTINUEASLONGASTHEREISENOUGHWATERINTHEGLASSTOKEEPTHEHEADWETHOWEVER,THEBIRDWILLCONTINUETODIPEVENWITHOUTASOURCEOFWATER,ASLONGASTHEHEADISWET,ORASLONGASATEMPERATUREDIFFERENTIALISMAINTAINEDBETWEENTHEHEADANDBODYTHISDIFFERENTIALCANBEGENERATEDWITHOUTEVAPORATIVECOOLINGINTHEHEADFORINSTANCE,AHEATSOURCEDIRECTEDATTHEBOTTOMBULBWILLCREATEAPRESSUREDIFFERENTIALBETWEENTOPANDBOTTOMTHATWILLDRIVETHEENGINETHEULTIMATESOURCEOFENERGYISHEATINTHESURROUNDINGENVIRONMENTTHETOYISNOTAPERPETUALMOTIONMACHINEDRINKINGBIRD1HEATENGINEAHEATENGINEISAPHYSICALORTHEORETICALDEVICETHATCONVERTSTHERMALENERGYTOMECHANICALOUTPUTTHEMECHANICALOUTPUTISCALLEDWORK,ANDTHETHERMALENERGYINPUTISCALLEDHEATHEATENGINESTYPICALLYRUNONASPECIFICTHERMODYNAMICCYCLEHEATENGINESAREOFTENNAMEDAFTERTHETHERMODYNAMICCYCLETHEYAREMODELEDBYTHEYOFTENPICKUPALTERNATENAMES,SUCHASGASOLINE/PETROL,TURBINE,ORSTEAMENGINESHEATENGINESCANGENERATEHEATINSIDETHEENGINEITSELFORITCANABSORBHEATFROMANEXTERNALSOURCEHEATENGINESCANBEOPENTOTHEATMOSPHERICAIRORSEALEDANDCLOSEDOFFTOTHEOUTSIDEOPENORCLOSEDCYCLEINENGINEERINGANDTHERMODYNAMICS,AHEATENGINEPERFORMSTHECONVERSIONOFHEATENERGYTOMECHANICALWORKBYEXPLOITINGTHETEMPERATUREGRADIENTBETWEENAHOT“SOURCE“ANDACOLD“SINK“HEATISTRANSFERREDFROMTHESOURCE,THROUGHTHE“WORKINGBODY“OFTHEENGINE,TOTHESINK,ANDINTHISPROCESSSOMEOFTHEHEATISCONVERTEDINTOWORKBYEXPLOITINGTHEPROPERTIESOFAWORKINGSUBSTANCEUSUALLYAGASORLIQUIDTHEPHISICSAROUNDTHEPHISICSAROUNDFIGURE1HEATENGINEDIAGRAMHEATENGINESAREOFTENCONFUSEDWITHTHECYCLESTHEYATTEMPTTOMIMICTYPICALLYWHENDESCRIBINGTHEPHYSICALDEVICETHETERMENGINEISUSEDWHENDESCRIBINGTHEMODELTHETERMCYCLEISUSEDINTHERMODINAMICS,HEATENGINESAREOFTENMODELEDUSINGASTANDARDENGINEERINGMODELSUCHASTHEOTTOCYCLE4STROKE/2STROKEACTUALDATAFROMANOPERATINGENGINE,ONEISCALLEDAINDICATORDIAGRAM,ISUSEDTOREFINETHEMODELALLMODERNIMPLEMENTATIONSOFHEATENGINESDONOTEXACTLYMATCHTHETHERMODYNAMICCYCLETHEYAREMODELEDBYONECOULDSAYTHATTHETHERMODYNAMICCYCLEISANIDEALCASEOFTHEMECHANICALENGINEONECOULDEQUALLYSAYTHATTHEMODELDOESNTQUITEPERFECTLYMATCHTHEMECHANICALENGINEHOWEVER,MUCHBENEFITISGAINEDFROMTHESIMPLIFIEDMODELS,ANDIDEALCASESTHEYMAYREPRESENTTHEPHISICSAROUNDINGENERALTERMS,THELARGERTHEDIFFERENCEINTEMPERATUREBETWEENTHEHOTSOURCEANDTHECOLDSINK,THELARGERISTHEPOTENTIALTHERMALEFFICIENCYOFTHECYCLEONEARTH,THECOLDSIDEOFANYHEATENGINEISLIMITEDTOCLOSETOTHEAMBIENTTEMPERATUREOFTHEENVIRONMENT,ORNOTMUCHLOWERTHAN300KELVINS,SOMOSTEFFORTSTOIMPROVETHETHERMODYNAMICEFFICIENCIESOFVARIOUSHEATENGINESFOCUSONINCREASINGTHETEMPERATUREOFTHESOURCE,WITHINMATERIALLIMITSTHEEFFICIENCYOFVARIOUSHEATENGINESPROPOSEDORUSEDTODAYRANGESFROM3PERCENT97PERCENTWASTEHEATFORTHEOTECOCEANPOWERPROPOSALTHROUGH25PERCENTFORMOSTAUTOMOTIVEENGINES,TO35PERCENTFORASUPERCRITICALCOALPLANT,TOABOUT60PERCENTFORASTEAMCOOLEDCOMBINEDCYCLEGASTURBINEALLOFTHESEPROCESSESGAINTHEIREFFICIENCYORLACKTHEREOFDUETOTHETEMPERATUREDROPACROSSTHEMOTECUSESTHETEMPERATUREDIFFERENCEOFOCEANWATERONTHESURFACEANDOCEANWATERFROMTHEDEPTHS,ASMALLDIFFERENCEOFPERHAPS25DEGREESCELSIUS,ANDSOTHEEFFICIENCYMUSTBELOWTHECOMBINEDCYCLEGASTURBINESUSENATURALGASFIREDBURNERSTOHEATAIRTONEAR1530DEGREESCELSIUS,ADIFFERENCEOFALARGE1500DEGREESCELSIUS,ANDSOTHEEFFICIENCYCANBELARGEWHENTHESTEAMCOOLINGCYCLEISADDEDINTHEPHISICSAROUNDTHERMODYNAMICCYCLESATKINSONCYCLEBRAYTON/JOULECYCLECARNOTCYCLECOMBINEDCYCLECROWERCYCLEDIESELCYCLEERICSSONCYCLEHIRNCYCLEKALINACYCLELENOIRCYCLELINDEHAMPSONCYCLEMILLERCYCLEMIXED/DUALCYCLEOTTOCYCLERANKINECYCLESCUDERICYCLEFIGURE1HEATENGINEDIAGRAMEXAMPLESOFEVERYDAYHEATENGINESINCLUDETHESTEAMENGINE,THEDIESELENGINE,ANDTHEGASOLINEPETROLENGINEINANAUTOMOBILEACOMMONTOYTHATISALSOAHEATENGINEISADRINKINGBIRDALLOFTHESEFAMILIARHEATENGINESAREPOWEREDBYTHEEXPANSIONOFHEATEDGASESTHEGENERALSURROUNDINGSARETHEHEATSINK,PROVIDINGRELATIVELYCOOLGASESWHICH,WHENHEATED,EXPANDRAPIDLYTODRIVETHEMECHANICALMOTIONOFTHEENGINEITISIMPORTANTTONOTETHATALTHOUGHSOMECYCLESHAVEATYPICALCOMBUSTIONLOCATIONINTERNALEXTERNAL,THEYOFTENCANBEIMPLEMENTEDASTHEOTHERCOMBUSTIONCYCLEFOREXAMPLE,JOHNERICSSONDEVELOPEDANEXTERNALHEATEDENGINERUNNINGONACYCLEVERYMUCHLIKETHEEARLIERDIESELCYCLEINADDITION,THEEXTERNALLYHEATEDENGINESCANOFTENBEIMPLEMENTEDINOPENORCLOSEDCYCLESWHATTHISBOILSDOWNTOISTHEREARETHERMODYNAMICCYCLESANDALARGENUMBEROFWAYSOFIMPLEMENTINGTHEMWITHMECHANICALDEVICESCALLEDENGINESTHEPHISICSAROUND2EVAPORATIONANDCONDENSATIONEVAPORATIONWATERCONDENSESINTOVISIBLEDROPLETSAFTEREVAPORATINGFROMACUPOFHOTTEAEVAPORATIONISTHEPROCESSWHEREBYATOMSORMOLECULESINALIQUIDSTATEGAINSUFFICIENTENERGYTOENTERTHEGASEOUSSTATETHEEQUIVALENTPROCESSINSOLIDSISKNOWNASSUBLIMATIONITISTHEOPPOSITEPROCESSOFCONDENSATIONEVAPORATIONISEXCLUSIVELYASURFACEPHENOMENAANDSHOULDNOTBECONFUSEDWITHBOILINGMOSTNOTABLY,FORALIQUIDTOBOIL,ITSVAPORPRESSUREMUSTEQUALTHEAMBIENTPRESSURE,WHEREASFOREVAPORATIONTOOCCUR,THISISNOTTHECASETHEVAPORPRESSUREOFALIQUIDISTHEPRESSUREEXERTEDBYITSVAPORWHENTHELIQUIDANDVAPORAREINDYNAMICEQUILIBRIUMTHEPHISICSAROUNDINCHEMISTRYANDPHYSICS,VAPORPRESSUREISTHEPRESSUREOFAVAPORINEQUILIBRIUMWITHITSNONVAPORPHASESALLSOLIDSANDLIQUIDSHAVEATENDENCYTOEVAPORATETOAGASEOUSFORM,ANDALLGASESHAVEATENDENCYTOCONDENSEBACKATANYGIVENTEMPERATURE,FORAPARTICULARSUBSTANCE,THEREISAPARTIALPRESSUREATWHICHTHEGASOFTHATSUBSTANCEISINDYNAMICEQUILIBRIUMWITHITSLIQUIDORSOLIDFORMSTHISISTHEVAPORPRESSUREOFTHATSUBSTANCEATTHATTEMPERATUREINMETEOROLOGY,THETERMVAPORPRESSUREISUSEDTOMEANTHEPARTIALPRESSUREOFWATERVAPORINTHEATMOSPHERE,EVENIFITISNOTEQUILIBRIUM,ANDTHEEQUILIBRIUMVAPORPRESSUREISSPECIFIEDASSUCHMETEOROLOGISTSALSOUSETHETERMSATURATIONVAPORPRESSURETOREFERTOTHEEQUILIBRIUMVAPORPRESSUREOFWATERORBRINEABOVEAFLATSURFACE,TODISTINGUISHITFROMEQUILIBRIUMVAPORPRESSUREWHICHTAKESINTOACCOUNTTHESHAPEANDSIZEOFWATERDROPLETSANDPARTICULATESINTHEATMOSPHERETHEPHISICSAROUNDVAPORPRESSUREISANINDICATIONOFALIQUIDSEVAPORATIONRATEITRELATESTOTHETENDENCYOFMOLECULESANDATOMSTOESCAPEFROMALIQUIDORASOLIDASUBSTANCEWITHAHIGHVAPORPRESSUREATNORMALTEMPERATURESISOFTENREFERREDTOASVOLATILETHEHIGHERTHEVAPORPRESSUREOFAMATERIALATAGIVENTEMPERATURE,THELOWERTHEBOILINGPOINTTHEVAPORPRESSUREOFANYSUBSTANCEINCREASESNONLINEARLYWITHTEMPERATUREACCORDINGTOTHECLAUSIUSCLAPEYRONRELATIONTHEBOILINGPOINTOFALIQUIDISTHETEMPERATUREWHERETHEVAPORPRESSUREEQUALSTHEAMBIENTATMOSPHERICPRESSUREATTHEBOILINGTEMPERATURE,THEVAPORPRESSUREBECOMESSUFFICIENTTOOVERCOMEATMOSPHERICPRESSUREANDLIFTTHELIQUIDTOFORMBUBBLESINSIDETHEBULKOFTHESUBSTANCEEVAPORATIONISACRITICALCOMPONENTOFTHEWATERCYCLE,WHICHISRESPONSIBLEFORCLOUDSANDRAINSOLARENERGYDRIVESEVAPORATIONOFWATERFROMOCEANS,LAKES,MOISTUREINTHESOIL,ANDOTHERSOURCESOFWATERINHYDROLOGY,EVAPORATIONANDTRANSPIRATIONWHICHINVOLVESEVAPORATIONWITHINPLANTSTOMATAARECOLLECTIVELYTERMEDEVAPOTRANSPIRATIONTHEPHISICSAROUNDCONDENSATIONCONDENSATIONISTHECHANGEINMATTEROFASUBSTANCETOADENSERPHASE,SUCHASAGASORVAPORTOALIQUIDCONDENSATIONCOMMONLYOCCURSWHENAVAPORISCOOLEDTOALIQUID,BUTCANALSOOCCURIFAVAPORISCOMPRESSEDIE,PRESSUREONITINCREASEDINTOALIQUID,ORUNDERGOESACOMBINATIONOFCOOLINGANDCOMPRESSIONLIQUIDWHICHHASBEENCONDENSEDFROMAVAPORISCALLEDCONDENSATEADEVICEORUNITUSEDTOCONDENSEVAPORSINTOLIQUIDISCALLEDACONDENSERCONDENSERSARETYPICALLYCOOLERSORHEATEXCHANGERSWHICHAREUSEDFORVARIOUSPURPOSES,HAVEVARIOUSDESIGNS,ANDCOMEINMANYSIZESRANGINGFROMRATHERSMALLHANDHELDTOVERYLARGECONDENSATIONOFVAPOROFLIQUIDISTHEOPPOSITEOFEVAPORATIONORBOILINGANDISANEXOTHERMICPROCESS,MEANINGITRELEASESHEATTHEWATERSEENONTHEOUTSIDEOFACOLDGLASSONAHOTDAYISCONDENSATIONTHEPHISICSAROUNDTHEPHISICSAROUNDCONDENSATIONOFWATERINNATUREDEWONASPIDERWEBWATERVAPORFROMAIRWHICHNATURALLYCONDENSESONCOLDSURFACESINTOLIQUIDWATERISCALLEDDEWWATERVAPORWILLONLYCONDENSEONTOANOTHERSURFACEWHENTHATSURFACEISCOOLERTHANTHETEMPERATUREOFTHEWATERVAPOR,ORWHENTHEWATERVAPOREQUILIBRIUMINAIR,IESATURATIONHUMIDITY,HASBEENEXCEEDEDWHENWATERVAPORCONDENSESONTOASURFACE,ANETWARMINGOCCURSONTHATSURFACETHEWATERMOLECULEBRINGSAPARCELOFHEATWITHITINTURN,THETEMPERATUREOFTHEATMOSPHEREDROPSVERYSLIGHTLYINTHEATMOSPHERE,CONDENSATIONOFWATERVAPOURISWHATPRODUCESCLOUDSTHEDEWPOINTOFANAIRPARCELISTHETEMPERATURETOWHICHITMUSTCOOLBEFORECONDENSATIONINTHEAIRBEGINSTOFORMALSO,ANETCONDENSATIONOFWATERVAPOROCCURSONSURFACESWHENTHETEMPERATUREOFTHESURFACEISATORBELOWTHEDEWPOINTTEMPERATUREOFTHEATMOSPHEREDEPOSITIONISATYPEOFCONDENSATIONFROSTANDSNOWAREEXAMPLESOFDEPOSITIONORSUBLIMATIONDEPOSITIONISTHEDIRECTFORMATIONOFICEFROMWATERVAPORTHEPHISICSAROUNDCONDENSATIONONACOLDBOTTLEOFWATERAPPLICATIONSOFCONDENSATIONBECAUSECONDENSATIONISANATURALLYOCCURRINGPHENOMENON,ITCANOFTENBEUSEDTOGENERATEWATERINLARGEQUANTITIESFORHUMANUSEINFACT,THEREAREMANYSTRUCTURESTHATAREMADESOLELYFORTHEPURPOSEOFCOLLECTINGWATERFROMCONDENSATION,SUCHASFOGFENCES,AIRWELLSANDDEWPONDSSUCHSYSTEMSCANOFTENBEUSEDTORETAINSOILMOISTUREINAREASWHEREACTIVEDESERTIFICATIONISOCCURRINGINFACT,CERTAINORGANIZATIONSUSEEDUCATIONABOUTWATERCONDENSERSINEFFORTSTOEFFECTIVELYAIDSUCHAREASTHEPHISICSAROUNDCONDENSATIONINBUILDINGSCONDENSATIONISTHEMOSTCOMMONFORMOFDAMPNESSENCOUNTEREDINBUILDINGSINBUILDINGSTHEINTERNALAIRCANHAVEAHIGHLEVELOFRELATIVEHUMIDITYDUETOTHEACTIVITYOFTHEOCCUPANTSEGCOOKING,DRYINGCLOTHES,BREATHINGETCWHENTHISAIRCOMESINTOCONTACTWITHCOLDSURFACESSUCHASWINDOWSANDCOLDWALLSITCANCONDENSE,CAUSINGDAMPNESS3IDEALGASLAWTHEPHISICSAROUNDTHEIDEALGASLAWISTHEEQUATIONOFSTATEOFAHYPOTHETICALIDEALGAS,FIRSTSTATEDBYBENOTPAULMILECLAPEYRONIN1834THESTATEOFANAMOUNTOFGASISDETERMINEDBYITSPRESSURE,VOLUME,ANDTEMPERATUREACCORDINGTOTHEEQUATIONWHEREISTHEPRESSUREPALISTHEVOLUMEM3ISTHEAMOUNTOFSUBSTANCEOFGASMOL,ISTHEGASCONSTANT83143M3PAK1MOL1,ANDISTHETEMPERATUREINKELVINSKTHEIDEALGASCONSTANTRISDEPENDENTONWHATUNITSAREUSEDINTHEFORMULATHEVALUEGIVENABOVE,8314472,ISFORTHESIUNITSOFPASCALCUBICMETERSPERMOLEKELVINANOTHERVALUEFORRIS0082057LATMMOL1K1THEIDEALGASLAWISTHEMOSTACCURATEFORMONATOMICGASESANDISFAVOREDATHIGHTEMPERATURESANDLOWPRESSURESITDOESNOTFACTORINTHESIZEOFEACHGASMOLECULEORTHEEFFECTSOFINTERMOLECULARATTRACTIONTHEMOREACCURATEVANDERWAALSEQUATIONTAKESTHESEINTOCONSIDERATIONTHEPHISICSAROUNDALTERNATEFORMSCONSIDERINGTHATTHENUMBEROFMOLESNCOULDALSOBEGIVENINMASS,SOMETIMESYOUMAYWISHTOUSEANALTERNATEFORMOFTHEIDEALGASLAWTHISISPARTICULARLYUSEFULWHENASKEDFORTHEIDEALGASLAWAPPROXIMATIONOFAKNOWNGASCONSIDERTHATTHENUMBEROFMOLESNISEQUALTOTHEMASSMDIVIDEDBYTHEMOLARMASSM,SUCHTHATTHEN,REPLACINGNGIVESINSTATISTICALMECHANICS,ANDISOFTENDERIVEDFROMFIRSTPRINCIPLESTHEPHISICSAROUNDHERE,KBISBOLTZMANNSCONSTANT,ANDNISTHEACTUALNUMBEROFMOLECULES,INCONTRASTTOTHEOTHERFORMULATION,WHICHUSESN,THENUMBEROFMOLESTHISRELATIONIMPLIESTHATNKBNR,ANDTHECONSISTENCYOFTHISRESULTWITHEXPERIMENTISAGOODCHECKONTHEPRINCIPLESOFSTATISTICALMECHANICSFROMHEREWECANNOTICETHATFORANAVERAGEPARTICLEMASSOFTIMESTHEATOMICMASSOFHYDROGEN,THEPHISICSAROUNDANDSINCEM/V,WEFINDTHATTHEIDEALGASLAWCANBEREWRITTENASPROOFEMPIRICALTHEIDEALGASLAWCANBEPROVEDUSINGROYLE,CHARLESANDGAYLUSSACLAWSCONSIDERANAMOUNTOFGASLETITSINITIALSTATEBEDEFINEDASVOLUMEV0PRESSUREP0TEMPERATURET0IFTHISGASNOWUNDERGOESANISOBARICPROCESS,ITSSTATEWILLCHANGEVOLUMEPRESSURETEMPERATURETHEPHISICSAROUNDTHEPHISICSAROUNDIFITTHENUNDERGOESANISOTHERMALPROCESSWHEREPFINALPRESSUREVFINALVOLUMETFINALTEMPERATURETSOWHERETHEPHISICSAROUNDTERMEDR,ISTHEUNIVERSALGASCONSTANTUSINGTHISNOTATIONWEGETANDMULTIPLYINGBOTHSIDESOFTHEEQUATIONBYNNUMBERSOFMOLESUSINGTHESYMBOLVASASHORTHANDFORNVVOLUMEOFNMOLESWEGETTHEORETICALTHEIDEALGASLAWCANALSOBEDERIVEDFROMFIRSTPRINCIPLESUSINGTHEKINETICTHEORYOFGASES,INWHICHSEVERALSIMPLIFYINGASSUMPTIONSAREMADE,CHIEFAMONGSTWHICHISTHATTHEMOLECULES,ORATOMS,OFTHEGASAREPOINTMASSES,POSSESSINGMASSBUTNOSIGNIFICANTVOLUMETHEPHISICSAROUNDLEVITRONTHELEVITRONISFORMEDBYATOPTHATHANGSABOVEABASEWHILEISSPINNINGTHEANTIGRAVITYFORCETHATREPELSTHETOPFROMTHEBASEISMAGNETISMBOTHTHETOPANDTHEHEAVYSLABINSIDETHEBASEBOXAREMAGNETIZED,BUTOPPOSITELYTHINKOFTHEBASEMAGNETWITHITSNORTHPOLEPOINTINGUP,ANDTHETOPASAMAGNETWITHITSNORTHPOLEPOINTINGDOWNTHEPRINCIPLEISTHATTWOSIMILARPOLESEG,TWONORTHSREPELANDTHATTWOOPPOSITEPOLESATTRACT,WITHFORCESTHATARESTRONGERWHENTHEPOLESARECLOSERTHEREAREFOURMAGNETICFORCESONTHETOPONITSNORTHPOLE,REPULSIONFROMTHEBASESNORTHANDATTRACTIONFROMTHEBASESSOUTH,ANDONITSSOUTHPOLE,ATTRACTIONFROMTHEBASESNORTHANDREPULSIONFROMTHEBASESSOUTHBECAUSEOFTHEWAYTHEFORCESDEPENDONDISTANCE,THENORTHNORTHREPULSIONDOMINATES,ANDTHETOPISMAGNETICALLYREPELLEDITHANGSWHERETHISUPWARDREPULSIONBALANCESTHEDOWNWARDFORCEOFGRAVITY,THATIS,ATTHEPOINTOFEQUILIBRIUMWHERETHETOTALFORCEISZEROASWELLASPROVIDINGAFORCEONTHETOPASAWHOLE,THEMAGNETICFIELDOFTHEBASEGIVESATORQUETENDINGTOTURNITSAXISOFSPINIFTHETOPWERENOTSPINNING,THISMAGNETICTORQUEWOULDTURNITOVERTHENITSSOUTHPOLEWOULDPOINTDOWNANDTHEFORCEFROMTHEBASEWOULDBEATTRACTIVETHATIS,INTHESAMEDIRECTIONASGRAVITYANDTHETOPWOULDFALLWHENTHETOPISSPINNING,THETORQUEACTSGYROSCOPICALLYANDTHEAXISDOESNOTOVERTURNBUTROTATESABOUTTHENEARLYVERTICALDIRECTIONOFTHEMAGNETICFIELDTHISROTATIONISCALLEDPRECESSIONWITHTHELEVITRON,THEAXISISNEARLYVERTICALANDTHEPRECESSIONISVISIBLEASASHIVERINGTHATGETSMOREPRONOUNCESASTHETOPSLOWSDOWNFORTHETOPITREMAINSUSPENDED,EQUILIBRIUMALONEISNOTENOUGHTHEEQUILIBRIUMMUSTALSOBESTABLE,SOTHATASLIGHTHORIZONTALORVERTICALDISPLACEMENTPRODUCESAFORCEPUSHINGTHETOPBACKTOWARDTHEEQUILIBRIUMPOINTLEVITRONFORTHELEVITRON,STABILITYISDIFFICULTTOACHIEVEITDEPENDSONTHEFACTTHATASTHETOPMOVESSIDEWAYS,AWAYFROMTHEAXISOFTHEBASEMAGNET,THEMAGNETICFIELDOFTHEBASE,ABOUTWHICHTHETOPSAXISPRECESSED,DEVIATESSLIGHTLYFROMTHEVERTICALIFTHETOPPRECESSEDABOUTTHEEXACTVERTICAL,THEPHYSICSOFMAGNETICFIELDSWOULDMAKETHEEQUILIBRIUMUNSTABLEBECAUSETHEFIELDISSOCLOSETOVERTICAL,THEEQUILIBRIUMISSTABLEONLYINASMALLRANGEOFHEIGHTSBETWEENABOUT125INCHESAND175INCHESABOVETHECENTEROFTHEBASEBETWEEN25AND30INCHESFORFASCINATIONSNEWSUPERLEVITRONTHEEARNSHAWTHEOREMISNOTVIOLATEDBYTHEBEHAVIOROFTHELEVITRONTHATTHEOREMSTATESTHATNOSTATICARRANGEMENTSOFMAGNETICORELECTRICCHARGESCANBESTABLE,ALONEORUNDERGRAVITYITDOESNOTAPPLYTOTHELEVITRONBECAUSETHEMAGNETINTHETOPISSPINNINGANDSORESPONDSDYNAMICALLYTOTHEFIELDFROMTHEBASELEVITRONTHEWEIGHTOFTHETOPANDTHESTRENGTHOFMAGNETIZATIONOFTHEBASEANDTHETOPDETERMINETHEEQUILIBRIUMHEIGHTWHEREMAGNETISMBALANCESGRAVITYTHISHEIGHTMUSTLIEINTHESTABLERANGESLIGHTCHANGESOFTEMPERATUREALTERTHEMAGNETIZATIONOFTHEBASEANDTHETOPASTHETEMPERATUREINCREASES,THEDIRECTIONSOFTHEATOMICMAGNETSRANDOMIZEANDTHEFIELDWEAKENSUNLESSTHEWEIGHTISADJUSTEDTOCOMPENSATE,THEEQUILIBRIUMWILLMOVEOUTSIDETHESTABLERANGEANDTHETOPWILLFALLBECAUSETHESTABLERANGEISSOSMALL,THISADJUSTMENTISDELICATETHELIGHTESTWASHERISONLYABOUT03OFTHEWEIGHTOFTHETOPTHETOPSPINSSTABLEINTHERANGEFROMABOUT20TO35REVOLUTIONSPERSECONDRPSITISCOMPLETELYUNSTABLEABOVE3540RPSANDBELOW18RPSAFTERTHETOPISSPUNANDLEVITATED,ITSLOWSDOWNBECAUSEOFAIRRESISTANCEAFTERAFEWMINUTESITREACHESTHELOWERSTABILITYLIMIT18RPSANDFALLSLEVITRONTHESPINLIFETIMEOFTHELEVITRONCANBEEXTENDEDBYPLACINGITINAVACUUMINAFEWVACUUMEXPERIMENTSTHATHAVEBEENDONETHETOPFELLAFTERABOUT30MINUTESW
温馨提示
- 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
- 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
- 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
- 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
- 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
- 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
- 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
最新文档
- 昭通学院《书写能力(钢笔)》2023-2024学年第二学期期末试卷
- 哈尔滨医科大学《食品加工类综合技能训练》2023-2024学年第二学期期末试卷
- 首都师范大学科德学院《设计思维》2023-2024学年第二学期期末试卷
- 江西泰豪动漫职业学院《植物病虫害防治实践》2023-2024学年第二学期期末试卷
- 浙江农业商贸职业学院《戏剧与教育理论及实践》2023-2024学年第二学期期末试卷
- 广州体育学院《蜜蜂生物学实验》2023-2024学年第二学期期末试卷
- 克拉玛依职业技术学院《交际口语(Ⅰ)》2023-2024学年第二学期期末试卷
- 广西大学《可摘局部义齿工艺学》2023-2024学年第二学期期末试卷
- 信阳学院《食品掺伪检验技术》2023-2024学年第二学期期末试卷
- 浙江工业职业技术学院《手工印染》2023-2024学年第二学期期末试卷
- 地理-2025年中考终极押题猜想(全国卷)
- 2024年广东省新会市事业单位公开招聘辅警考试题带答案分析
- 广安2025年上半年广安市岳池县“小平故里英才”引进急需紧缺专业人才笔试历年参考题库附带答案详解
- 派特灵用于女性下生殖道人乳头瘤病毒感染及相关疾病专家共识(2025年版)解读
- 数字化转型背景下制造业产业链协同创新机制研究
- 贵州大学语文试题及答案
- 公司主体变更劳动合同补充协议7篇
- 质量月建筑工程质量知识竞赛考试题库500题(含答案)
- 早产儿经口喂养临床实践专家共识(2025)解读
- 汽车快修连锁加盟商业计划书
- DB33T 1376-2024乡镇(街道)应急消防管理站建设与运行规范
评论
0/150
提交评论