高三英语UNIT2 sailing the ocean人教版　选修9.ppt

sailingtheocean warmingup whatisanavigator whatisthedifferencebetweenanavigatorandanexplorer anavigatorexploresnewroutesacrossthesea anavigatorexploresthesea anexplorerdiscoversnewplacesonland navigator sea nauticalinstruments findnewislandsorcontinents navigatorissb whofindsthepositionandplotsthecourseofashipbyusingmapsandnauticalinstruments explorer land useofcompassandlandmarks findnewplaceswithinanalreadyidentifiedislandorcontinent explorerissb whotravelsintoorthroughaplaceinordertolearnaboutit canyouidentifytheseearlynavigationalinstrumentsseamenused howdotheywork compass astrolabe sextant abearingcircle abearingcircle 方位圆 thefirstinstrumenttomeasurethesun spositionandthesun sshadow aquadrant aspecialtoolfortellingthepositionoftheshipinrelationtothesunandvariousstars anastrolabe measurehowhighstarswereabovethehorizon a longitude latitude anupdatednavigationalinstrumenttomeasuretheanglebetweentwofixedpointsoutsidetheship sextant anautical seachart reading readaboutwhatnavigationwaslikebeforemoderninstrumentswereused sailingtheoceans fast readingtogetthegeneralidea page1 readthepassageandanswerthefollowingquestions whatistheuseofabearingcircle astrolabe quadrantorsextant whatistheuseofacompass a tosetthecourseoftheshipb tomeasurethepositionoftheshipc tomeasurethespeedoftheshipd totellthetime b a returninghomeintheeveningorfog freshseaweed nestingbirds 2 usetheinformationtoanalyzethenavigationalskillsandwritetheanswersinyourownwords tofindtheship spositionatseaasailoruse asailorknewthatlandwasnearbyifhesaw sailorsused toincreasetheirspeed thenorthstarandthesun seacurrentortidesand winds usingnature keepingalongsidethecoastlineusingcelestialbodiesusingwildlifeusingtheweatherusingthesea usingcelestialbodies toplotthepositions toworkoutthelatitude aspecialcloudformationindicatesthereislandcloseby usingwildlife ifseaweedwasfreshandsmelledstrongly theshipwasclosetoland seabirdscouldbeusedtoshowthewaytolandwhenitwasnowheretobeseen usingtheweather fog tohelpidentifythepositionofastreamorriverwhentheywereclosetoland todirecttheirsailing fast readingtogetthegeneralidea thenanswerthequestions page2 1 whyarespeedandtimeimportantinworkingoutthelongitudeofaship speedandtimeareimportantinfindingoutthelongitudeofashipbecausetheearthmovesfifteendegreeswestwardseveryhour ifyouknowyourdirection speedandtime youcanworkouttheapproximatelongitudeorchangeinyourpositioninrelationtothestars 2 whyisthepositionofthesunandvariousstarsusefulforworkingoutlatitude thepositionofthesunandstarsareusefulforworkingoutlatitudebecausetheyarefixedpointsintheskyandtheirmovementsinrelationtotheeartharealreadyknown sotheycanbeusedtomeasureaship sposition readagainandfillintheblanks thereweretwomethodstofindlongitude 1 2 measuringtimeandspeed compassandcomplicated mathematicaltables writedowntheworkingprinciplesofthefollowinginstruments bearingcircle astrolabe quadrant sextant tocomparetheheightofthesunnowwiththepositionofthesunatmidday tocomparethepositionoftheshipinrelationtosomestarsorthesun amorepreciseformoftheastrolabe tomeasurehowhighstarsareabovethehorizon andcomparethatmeasurementwithpreviousmeasurements anupdatedversionofthequadrantandsoitwasmoreaccurate tomeasuretheanglebetweentowfixedpointsoutsidetheship horizon sunheight abaringcircle bearingthesun heightandazimuth themarkswereusedtomeasuretheshadowofthesunanditsheightandpositioninthesky discuss supposeyourwereaseacaptainaimingtosailroundafrica 1 whatskillswouldyouseekinyoursailors 2 whatproblemswouldyouanticipateforthisjourney 1 whatskillswouldyouseekinyoursailors thesailorswouldneedtobeexcellentnavigators abletocopewithbothhotandcoldweather experiencedinsailingthroughverybadweatherandabletoco operateinateam 2 whatproblemswouldyouanticipateforthisjourney iwouldanticipateveryhotweather aroundtheequator coldweather aroundcapeofgoodhope verystormyseas aroundthecape andproblemswithfoodandwater etc whatwouldyoudoifyoucameacrossthefollowingproblemsduringyourvoyage waittillthestormisover andthenfindyournewpositionandreturntoyouroriginalcourse useknotstofindyourspeedandworkoutyourapproximatelongitude usethecompassandtheastrolabe quadrantorsextanttofindoutyourposition returntoyourformercourse follownestingbirdstoshore lookforspecialcloudformationsorfogoverstreamstofindland useacompass measureyourpositionusingthesunorstars lookforseabirds cloudformations fogorseaweedtoshowthatlandisnearby whatwouldyouneedforaweek sjourneyacrossthenorthseatoengland shirt trousers soap blanket waterproofboots knife scissors sea sicktablets learningaboutlanguage discoveringusefulwordsandexpressions replacethewordsunderlinedbyonesofsimilarmeaningfromthereadingpassage seeingthedarkcloudsabovehim georgehurriedforhome sailingaboatalonefarawayfromtheshoremadeflora sparentsworryabouthersafety clare wouldyoupleaseputyourbicyclenexttotheothersintheshed offshore overhead alongside 4 whydon tyouplotamoresimpleroutewiththesmallestnumberofstops askedmary 5 settingoutonalongjourneybyseawithunskilledsailorswouldbedangerousespeciallyiftherewerenomodernnavigationalinstruments simplified voyage seamen findthewordsfromthereadingpassagethataretheoppositeofthesecompoundwords anywhereuploadinwardunreliablelandflowerstrongpoint nowhere download outward reliable seaweed shortcoming writedownthewordsyouknow whicharerelatedtonavigationandsea navigation sail sailor voyage latitude longitude equator horizon captain landisland nauticalmiddles explore exploration sea seaman seaweed seafood shore offshore onshore beach beach ball seabed sea bird seagull seashell seaside seawater seasick coast coastline tide wave current completethefollowingparagraphwiththewordsbelow preciseoutwardnowhereawkwardreferenceseaweedacceleratemercyrandomlyvoyagealongsideapproximate samuelthesailorwasextremelygoodatplottinghiscourseusingthestarsasa onedayhewasdeterminedtosetoutona acrossanunknownseatoanunknowncontinent hesetoutwithhisinstrumentssohewouldnotbeatthe ofthesea hefoundonhis journeyarockyisland itseemedtobecoveredinnest suddenly assamuellooked