高中英语 Sailing the oceans-Textbook课件 新人教版选修9 课件VIP免费

Inpairsdiscussthesequestions:1Whatisanavigator?Anavigatorexploresnewroutesacrossthesea.2Whatisthedifferencebetweenanavigatorandanexplorer?Anavigatorexploresthesea;anexplorerdiscoversnewplacesonland.WarmingUp3Lookatthesefamouspeople.Aretheynavigatorsorexplorers?Whatdoyouknowaboutthem?NavigatorseanauticalinstrumentsfindnewislandsorcontinentsNavigatorissomeonewhofindsthepositionandplotsthecourseofaship,anaircraft,acar,etc,usingmapsandinstruments.ExplorerlanduseofcompassandlandmarksfindnewplaceswithinanalreadyidentifiedislandorcontinentExplorerissomeonewhotravelsintoorthroughaplaceinordertolearnaboutit.Veryoftennavigatorsarealsoexplorers.•Lookatthepictures.Thenanswerthequestions.1Howdoyouthinkseamenfoundtheirwaybeforemodernaccuratemethodsofnavigationwereinvented?Keptclosetotheshore,usednaturesuchasthesun,wind,birds,tide,etc,tohelpthem,andusedsomeoftheinstrumentsincludingacompass,astrolabe,etc.Pre-reading2Whichdoyouthinkwaseasiertoworkout:latitudeorlongitude?Latitude,becauseitwasusedtomeasurehowfaryouhadtravelledfromlandonastraightline.Itwasdiscoveredalongtimebeforelongitude.3Canyouidentifytheseearlynavigationalinstrumentsseamenusedandexplainhowtheyareused?1_________________________2_________3_________4________________________4Whichonesdoyouthinkarestillusedtoday?Seachartsarestillusedtoday.compass(inancientChina)astrolabesextantsea/nautical/marinechartReadthepassageandanswerthefollowingquestions.1Whatistheuseofabearingcircle,astrolabe,quadrantorsextant?()Whatistheuseofacompass?()AtosetthecourseoftheshipBtomeasurethepositionoftheshipCtomeasurethespeedoftheshipDtotellthetimeComprehending1BA2Whyarespeedandtimeimportantinworkingoutthelongitudeofaship?Speedandtimeareimportantinfindingoutthelongitudeofashipbecausetheearthmovesfifteendegreeswestwardseveryhour.Ifyouknowyourdirection,speedandtime,youcanworkouttheapproximatelongitudeorchangeinyourpositioninrelationtothestars.3Whyisthepositionofthesunandvariousstarsusefulforworkingoutlatitude?Thepositionofthesunandstarsareusefulforworkingoutlatitudebecausetheyarefixedpointsintheskyandtheirmovementsinrelationtotheeartharealreadyknown.Sotheycanbeusedtomeasureaship'sposition.SupposeyouwereaseacaptainaimingtosailroundAfrica.Discussingroups:1Whatskillswouldyouseekinyoursailors?Thesailorswouldneedtobeexcellentnavigators,abletocopewithbothhotandcoldweather,experiencedinsailingthroughverybadweatherandabletoco-operateinateam.22Whatproblemswouldyouanticipateforthisjourney?Iwouldanticipateveryhotweather(aroundtheequator),coldweather(aroundtheCapeofGoodHope),verystormyseas(aroundtheCape),andproblemswithfoodandwater(unlesshelpedbylocalnativesthewatermaybecontaminatedandthefoodscarce),etc.Whatwouldyoudoifyoucameacrossthefollowingproblemsduringyourvoyage?Readthechartbelowandfillinyourplansofactiontodealwiththem.3Whatwouldyoudoif:PlanofactionYouwerefarfromlandandastormarose.waittillthestormisover,andthenfindyournewpositionandreturntoyouroriginalcourseYouknewyourlatitudebutdidn'tknowyourlongitude.Youwereblownoff-course.useknotstofindyourspeedandworkoutyourapproximatelongitudeusethecompassandtheastrolabe,quadrantorsextanttofindoutyourposition,returntoyourformercourseYouwereoffshorebutyouneededmorefoodandwater.Youwantedtokeepastraightcourse.follownestingbirdstoshore;lookforspecialcloudformationsorfogoverstreamstofindlanduseacompassYouwerelostwithnolandi...