2015 hsc engineering studies - board of studies · pdf fileengineering studies. ... aluminium...

2200

2015 HIGHER SCHOOL CERTIFICATE EXAMINATION

Engineering Studies

General Instructions

•Readingtime–5minutes

•Workingtime–3hours

•Writeusingblackpen

•Drawdiagramsusingpencil

•Board-approvedcalculatorsmaybeused

•Aformulaesheetisprovidedatthebackofthispaper

•WriteyourCentreNumberandStudentNumberatthetopofpages13,17,19,21,25,27and35

Total marks – 100

Section I Pages 2–11

20 marks

•AttemptQuestions1–20

•Allowabout30minutesforthissection

Section II Pages13–35

80 marks

•AttemptQuestions21–27

•Allowabout2hoursand30minutesforthissection

– 2 –

Section I

20 marksAttempt Questions 1–20Allow about 30 minutes for this section

Usethemultiple-choiceanswersheetforQuestions1–20.

1 Whichofthefollowinghasbothmagnitudeanddirection?

(A) Mass

(B) Scalar

(C) Speed

(D) Vector

2 WhichofthefollowingmethodswouldbesuitabletomanufacturePETpolymerbottles?

(A) Casting

(B) Pressing

(C) Stamping

(D) Blowmoulding

3 Amotorvehicleistravellingalongahorizontalroad.

Howdoesanincreaseinvelocityaffectitspotentialenergyandkineticenergy?

Potential energy Kinetic energy

(A) Increases Increases

(B) Maintains Increases

(C) Increases Decreases

(D) Maintains Decreases

–3–

4 Apictorialviewofablockisshown.

Front View

Whichsetofviewsrepresentstheblockinorthogonalprojection?

(A) (B)

(C) (D)

5 Theteethonasteelsprocketneedtobehard.

Sprocket teeth

Whichheattreatmentprocessismostsuitableforhardeningtheteeth?

(A) Flameheatingthenaircooling

(B) Flameheatingthenovencooling

(C) Inductionheatingthenquenching

(D) Inductionheatingthenslowcooling

– 4 –

6 Whichprocesscombinesdataandacarrierwavetoformatelevisionsignal?

(A) Compressing

(B) Encryption

(C) Modulation

(D) Multiplexing

7 Which of the lever systems would require the least force at X to balance the 100kgmass?

X100 kg

(A)

X100 kg

(C)

X100 kg

(B)

X100 kg

(D)

–5–

8 Whichstatementbestdescribesthedifferencebetweencastironandsteel?

(A) Steelcontainsmorefreegraphite.

(B) Castironhashighertensilestrength.

(C) Steelhashighercompressivestrength.

(D) Castironhasahigherpercentageofcarbon.

9 WhichformoftheACtoDCrectificationprocessisshownbythegraphs?

Before rectification

V

t

After rectification

V

t

(A) Fullwave

(B) Halfwave

(C) Smoothfullwave

(D) Smoothhalfwave

10 Theheatsinkshownisusedtoconductheatawayfromcomponents.

Heat sink

Whichrowofthetableidentifiesasuitablematerialandmanufacturingprocessfortheheatsink?

Material Manufacturing process

(A) Steel Rolling

(B) Nylon Injectionmoulding

(C) Aluminiumalloy Diecasting

(D) Ceramic Compressionmoulding

– 6 –

11 Considerthislogiccircuitforturningalamponoroff.

Switch 1

Lamp

Switch 2

Switch 3

Whichsetofconditionswillturnthelampon?

Switch 1 Switch 2 Switch 3

(A) Off Off Off

(B) On On On

(C) Off Off On

(D) Off On On

12 Eachresistorinthediagramsbelowhasavalueof10W.

Whichcombinationofresistorsprovidesatotalresistanceof15WbetweenXandY ?

(A)

(B)

(C)

(D)

X Y

X Y

X Y

X Y

–7–

13 Inwhichdirectiondoesareactionforceactatarollersupport?

(A) Paralleltothesupportingsurface

(B) Verticaltothesupportingsurface

(C) Horizontaltothesupportingsurface

(D) Perpendiculartothesupportingsurface

14 The image shows one end of an electrical spark plug used in an internal combustionengine.

M

WhichcombinationofpropertieswouldthecomponentlabelledMneedtohave?

(A) Electricalresistivityandmachinability

(B) Electricalconductivityandmachinability

(C) Electricalresistivityandtemperaturestability

(D) Electricalconductivityandtemperaturestability

– 8 –

15 Whichgraphbestrepresentstherelativeproportionsofmaterialsusedintheconstructionofnew,largepassengeraircraft?

(A) (B)

Aluminiumalloy

Composite

Titanium

Steel

Other

Composite

Aluminiumalloy

Titanium

Steel

Other

(C) (D)

Composite

Steel

Titanium

Aluminiumalloy

Other

Aluminiumalloy

Titanium

Composite

Steel

Other

–9–

16 Apoleissupportedbyfourcablesthatareattachedtoitstopandtotheslopingground.

3

34

21

2

4

1

Whichcableisshownastruelength?

(A) Cable1

(B) Cable2

(C) Cable3

(D) Cable4

17 Whichofthefollowingcouldcausefatiguecrackinginametal?

(A) Astatictensileload

(B) Asubstantialshockload

(C) Ahighcompressionload

(D) Acyclicallyappliedload

– 10 –

18 What are TWO advantages of using the powder forming process to manufacture aself-lubricatingbearing?

(A) Lowmaterialwasteandhighdensity

(B) Highporosityandlowmaterialwaste

(C) Lowdensityandhightensilestrength

(D) Highqualitysurfacefinishandhightensilestrength

19 The diagram shows one end of a universal ‘I’ beam with access holes drilled and asupportingbracketfixedtoeachside.

X

X

WhichviewshowsthecorrectfullsectionX−Xofthebeamviewedinthedirectionofthearrows?

(A) (B)

(C) (D)

– 11 –

20 Thedrawingrepresentsaloadedsteelbeamsimplysupportedateachend.

2 m 5 m 1 m

7 kN3 kN

5.1 kN 8.9 kN

UDL 500 N/m

(A)

0

(B)

0

(C)

0

(D)

0

Whichdiagrambestrepresentsthedistributionofshearforcesalongthebeam?

2 m 5 m 1 m

7 kN3 kN

5.1 kN 8.9 kN

UDL 500 N/m

(A)

0

(B)

0

(C)

0

(D)

0

BLANK PAGE

© 2015 Board of Studies, Teaching and Educational Standards NSW

– 12 –

–13–

CentreNumber

StudentNumber

2201


Engineering Studies

Section II

80 marksAttempt Questions 21–27Allow about 2 hours and 30 minutes for this section

Answerthequestionsinthespacesprovided.Thesespacesprovideguidancefortheexpectedlengthofresponse.

Question 21 (11marks)

Please turn over

– 14 –


(a) ThesketchshowsanearlyAustralian-builtcar.

ExplainhowTWOfeaturesofthisearlyAustralian-builtcarhavebeenmodifiedinmoderncarstoimprovetheirsafety.

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3

Question 21 continues on page 15

–15–

Question21(continued)

(b) Thediagramrepresentspartofacar’shydraulicbrakingsystem.

Brake disc

Brake caliper

Brake pedalBrake master

cylinder

Outline the operation of this hydraulic system and its advantages overmechanicalsystems.

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4


– 16 –


(c) Ahydrauliccylindersystemisshown.

Cylinder A has a piston area of 100mm2. Cylinder B has a piston area of700mm2.

A B

X

Y

(i) CalculatetheforceonrodYwhenaforceof50NisappliedonrodX. 2

.........................................................N

(ii) CalculatethedistancerodYwouldmovewhenrodXmoves60mm.

..................................................... mm

2

End of Question 21

©2015BoardofStudies,TeachingandEducationalStandardsNSW

–17–

CentreNumber

StudentNumber

2202


Engineering Studies

Section II (continued)


(a) Acircuitdiagramofasimpleradioreceiverisshown.

B

A

NamethecomponentslabelledAandBandoutlineeachcomponent’sfunctioninthiscircuit.

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4

(b) Howhavesemi-conductorsinfluencedthedesignofmoderntelecommunicationsproducts?

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2


– 18 –


(c) Aradioaerialsupportbracketboltedtoasteelplateisshown.Completeafullysectionedfrontviewofthebracketassembly.ApplyAS1100.

6

A A

End of Question 22


–19–

CentreNumber

StudentNumber

2203


Engineering Studies



(a) Animageofatelephonechargerisshown.

Pins

Cover

(i) Thematerialusedfortheelectricalpinsofthetelephonechargerneedstobeagoodconductorofelectricity.

List TWO other engineering properties that would be relevant whenselectingthematerialforthepins.

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2

(ii) Thetelephonechargercoveristobemanufacturedfromapolymer.

Nameanddescribeasuitablemanufacturingprocess.

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3


– 20 –


(b) Contrastthekeyfeaturesoffixedandmobiletelephonesystems.

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3

(c) A smart-phone transmits digital information. One step in this process is toconvertanaloguevoicedatatodigitiseddata.

Analogue signal

T

V

Digitised signal

T

V

4

Outlinehowananaloguesignalisdigitisedusingsamplingandquantising.

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End of Question 23


– 21 –

CentreNumber

StudentNumber

2204


Engineering Studies



(a) Thephotographshowsrailwaypowercablessupportedbyasteelcolumn.

(i) Suggestasuitablemethodthatcouldbeusedtoprotectthissteelcolumnfromcorrodingandexplainhowthismethodslowsthecorrosionprocess.

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2

(ii) Thecolumnismanufacturedbycoldrolling0.4%carbonsteel.

Sketchandlabeltheresultingmicrostructure.

2


– 22 –


(b) A diagram of a pin-jointed, cantilever truss that supports overhead railwaypowercablesisshown.

1.5 m

1.5

m

1.5 m 1.5 mCB

A

F

D E

750 N

1200 N

Aweightof1200NisdeterminedtobeactingatjointCandthepowercableweightof750NisactingatjointE.

(i) DeterminethemagnitudeofthereactionatsupportA. 2

MagnitudeofreactionatA................................N


–23–


(ii) Determine the magnitude and the direction of the reaction at the pinjointB.

3

ReactionatB.................................N Direction...................................

(iii) DeterminethemagnitudeandthenatureoftheforceinmemberAC. 3

ForceinAC.................................... N Nature.......................................

End of Question 24

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– 24 –

–25–

CentreNumber

StudentNumber

2205


Engineering Studies



(a) Thetwoimagesshowlightaircraftpoweredbydifferentpropulsionsystems. 3

Business aircraft Recreational aircraft

Identifyasuitablepropulsionsystemforeachaircraftandjustifyyourchoice.

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(b) OutlineTWOcontroladjustmentsthatcanbemadetovarytheliftforceactingonanaircraftduringflight.

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3


– 26 –


(c) Anaerofoilwastestedinawindtunnel.

Thistestproducedaresultantforceof350Natanangleof10°totheliftaxis.

2

10°Air flow

Calculatethelifttodragratio.

LifttoDragRatio...............................

(d) Outline the ultrasonic testing process and its advantages for use in testingaircraftcomponents.

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4

End of Question 25


–27–

CentreNumber

StudentNumber

2206


Engineering Studies



Please turn over

– 28 –

Question 26 (13 marks)

(a) A winch mechanism is used to pull a 150 kg crate up a ramp and onto a transport vehicle.

25°

150 kg Ramp

Cable

Crate

Winch

The winch cable is parallel to the ramp.

(i) A simplified sketch of the crate, ramp and the tensile force (T) in the cable is shown at the point of the crate sliding up the ramp.

Add labelled arrows to the sketch to indicate the following forces:

• normal

• weight

• friction.

T

2

(ii) Calculate the tensile force in the cable at this point if the coefficient of friction between the crate and the ramp is 0.3.

3

Tension in cable ............................ N


–29–


(iii) Foradifferentsituation,thetensioninthecableis910N.Thiswinchis85%efficientandhasaneffectivedrumdiameterof100mm.

What is the minimum force (F) required to operate this winch if theeffectivelengthofthewinchhandleis350mm?

2

35

0

F

T = 910 N Ø100

Force............................................... N


–30–


(b) Thesteelusedtomanufacturethewinchcablewastestedusingatensometerandtheresultingdetailsareshownontheload−extensiongraph.

0.50

10

20

30

1 1.5

Extension (mm)

Loa

d (k

N)

2

X

Y

Z

(i) Statethesignificanceofthethreekeypointsidentifiedonthegraph. 3

X ...............................................................................................................

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Y ...............................................................................................................

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Z ...............................................................................................................

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–31–


(ii) The original gauge length of the steel test piece was 55mm with across-sectionalareaof9.6mm2.

Using data from the load−extension graph, calculate the value ofYoung’sModulusforthissteel.

3

Young’sModulus.......................................... GPa

End of Question 26

Question 27 starts on page 35

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–32–

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–33–

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– 34 –

–35–

CentreNumber

StudentNumber

2207


Engineering Studies



An engineering team consists of a civil engineer, an electrical engineer and anenvironmentalengineer.Theyhavebeencontractedbyalocalcounciltomanagethedesignandconstructionofafivemetrelongpedestrianbridgeacrossanarrowcreekinapublicpark.

Outlinehoweachof theseengineerswouldcontribute to thesuccessfulcompletionofthisproject.

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End of paper

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– 36 –

–37–2208


Engineering Studies

FORMULAE SHEET

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– 38 –

2015 hsc engineering studies - board of studies · pdf fileengineering studies. ... aluminium...

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