MovementAnalysis

LeverSystemsGCSEPE

HelpfulWebsitesbeforeyoubegin

WatchtheYoutubevideobelow(PlanetPE)!GoodExplanationofLeversystems

•  https://www.youtube.com/watch?v=9-oFDZYsd5Q

•  https://www.bbc.co.uk/bitesize/guides/zxkr82p/revision/1

Terms

•  3keytermsyouneedtoknow

•  Fulcrum:

•  Effort:

•  Load:

Pivot.Inthebodythisisajoint.Theforceappliedtomovetheobject.Inthebodythiswillbeamuscularcontraction.Theloadtobemoved,usuallyaweightortheweightofthebody.

LeverClassesThreeclassesoflever:•  ClassOne:

•  Fulcruminthemiddle•  ClassTwo:

•  Loadinthemiddle

•  ClassThree:•  Effortinthemiddle

ClassOne•  FoundintheNeck•  Identify:– Fulcrum– Effort– Load

Trapezius

Cranium+Mandible

PivotJointatNeck

ClassTwo•  FoundintheAnkle•  Identify:– Fulcrum– Effort– Load

Gastrocnemius

WeightofbodythoughTibia

BaseofToe

ClassThree•  FoundintheElbow•  Identify:– Fulcrum– Effort– Load

Bicep

HandandObject

Elbow-Hinge

•  Usingslides4/5/6completeWorksheet1

Oneachofthe3diagramsyoumust!•  Nameeachleverandlabelthe:-Fulcrum-Effort-Load•  Onboththebodypartandthelever.•  Namethemusclethatiscreatingtheeffort?

Task1

Task2

•  OnWorksheet2•  Cutoutandannotatetheimagewiththethreelevers(likeinslide4/5/6)

•  Explainreasonsforyouranswer(Refertopositioningofeffort,loadandfulcrum).

•  Usingthekeybelow,labelthefollowingincludingthedirectionofloadandeffort.

-Load

-Effort

-Fulcrum

1,2,3/F,L,E

•  HowdoIrememberwhateachLeverlookslike?!•  Here’sacoupleoftips,Canyouthinkofyourown?–  1,2,3–F,L,E

•  Class1hastheFulcruminthemiddle(F),•  Class2hastheLoadinthemiddle(L),•  Class3hastheEffortinthemiddle(E).

–  NAE–Neck,Ankle,Elbow(1,2,3)

MechanicalAdvantage

•  Dependsonthedistancebetweentheeffortandthefulcrum(Effortarm)

•  Comparedtothedistancebetweenthefulcrumandtheresistance(Resistancearm)

•  Themechanicaladvantageisworkedoutbydividingtheeffortarmbytheresistancearm:

MA=Effortarm÷Resistancearm

•  AshortLoadArmallowsaheavierloadtobelifted.

•  AshortEffortArmallowsforfastermovementsoveralargerrange.

LoadArm

EffortArm

Type2Lever

Type3Lever

MechanicalAdvantage•  WhenaLeversEffortArmislongerthanitsLoadArm.

•  SecondClassLeversALWAYShaveamechanicalAdvantage.

Theycanmovelargeloadswithlesseffort

MechanicalDisadvantage

•  WhenaLeversLoadArmislongerthantheEffortArm.

•  ThirdClassLeversALWAYShaveaMechanicalDisadvantage

Althoughtheyareata‘disadvantage’theycanincreasethespeedofthe

leverarm.

AdvantageofDisadvantage?

•  WithFirstClassLeversthisdependsonthepositionoftheFulcrum.

Task

1.  Onyourworksheetdraweachlever.2.  Giveanexampleofwhereitwouldbe

locatedonthebody.3.  DescribetheMechanicalAdvantageor

Disadvantage.4.   Extension:Turnoverthepageandseeifyou

candrawandidentifyotherexamplesofleverinthebody.

Skilledperformanceismadepossiblethroughtheeffectiveuseofleversystems.a)Sketchandlabelathirdclassleversystem.(3marks)b)Inyourdiagram,drawandlabeltheeffortarmandtheresistancearm.(2marks)c)Whataretheadvantagesanddisadvantagesofthirdclassleversovertheothertypesofleversystems?(2marks)

ExamQuestion(Answers)

•  Thirdclassleverhasashortereffortarmandalongerresistancearm.

•  Thisresultsinamechanicaldisadvantageintermsoftheamountofweightthatcanbeliftedduetotheshorteffortarm.

•  However,thereisthemechanicaladvantageofalargerangeofmovementandgreaterspeedofmovementduetolongresistancearm.

EffortResistance

Fulcrum

Effortarm

Resistancearm

AnswerQ1+2

AnswerQ3

Task4

•  CompleteWorksheet3’Leversandsportingexamples’

•  CompleteexamquestionsonWorksheet4•  Usemarkschemetocheckyouranswers•  Answerquestionsbeforeyoulookatmarksheet!!

Task5