2017 Physics-nht Written examination - Pages

PHYSICSWritten examination

Monday 5 June 2017 Reading time: 10.00 am to 10.15 am (15 minutes) Writing time: 10.15 am to 12.45 pm (2 hours 30 minutes)

QUESTION AND ANSWER BOOK

Structure of bookSection Number of

questionsNumber of questions

to be answeredNumber of

marks

A – Motion in one and two dimensions 6 6 40 Electronics and photonics 5 5 22 Electric power 5 5 36 Interactions of light and matter 5 5 30

B – Materials and their use in structures 11 11 22Total 150

• Students are permitted to bring into the examination room: pens, pencils, highlighters, erasers, sharpeners, rulers, pre-written notes (one folded A3 sheet or two A4 sheets bound together by tape) andonescientificcalculator.

• Students are NOT permitted to bring into the examination room: blank sheets of paper and/or correctionfluid/tape.

Materials supplied• Questionandanswerbookof43pages.• Formulasheet.• Answersheetformultiple-choicequestions.Instructions• Writeyourstudent numberinthespaceprovidedaboveonthispage.• Checkthatyourname and student number as printed on your answer sheet for multiple-choice

questionsarecorrect,andsignyournameinthespaceprovidedtoverifythis.• Unlessotherwiseindicated,thediagramsinthisbookarenotdrawntoscale.• AllwrittenresponsesmustbeinEnglish.At the end of the examination• Placetheanswersheetformultiple-choicequestionsinsidethefrontcoverofthisbook.• Youmaykeeptheformulasheet.

Students are NOT permitted to bring mobile phones and/or any other unauthorised electronic devices into the examination room.

©VICTORIANCURRICULUMANDASSESSMENTAUTHORITY2017

SUPERVISOR TO ATTACH PROCESSING LABEL HEREVictorian Certificate of Education 2017

STUDENT NUMBER

Letter

2017PHYSICSEXAM(NHT) 2

THIS PAgE IS BlANK

3 2017PHYSICSEXAM(NHT)

TURN OVER

Table of contents

SECTION A

Area of study Page

Motion in one and two dimensions.............................................................................................................. 4

Electronics and photonics............................................................................................................................ 14

Electric power.............................................................................................................................................. 22

Interactions of light and matter.................................................................................................................... 32

SECTION B

Detailed study

Materials and their use in structures............................................................................................................ 40

2017 PHYSICS EXAM (NHT) 4

SECTION A – Core studies – Question 1 – continued

Area of study – Motion in one and two dimensions

Question 1 (8 marks)A tugboat is towing two barges (unpowered boats) connected by cables, as shown in Figure 1.The tugboat has a mass of 100 tonnes and each barge has a mass of 200 tonnes.

100 tonnes 200 tonnes 200 tonnes

tugboatBarge 1 Barge 2

Figure 1

The tugboat starts from rest and accelerates at 0.50 m s–2.

a. Calculatethedistancethatthetugboatanditsbargestravelinthefirst10s. 2 marks

m

b. Calculate the force applied by the tugboat’s engine. Ignore any friction. 2 marks

N

SECTION A – Core studies

Instructions for Section AAnswer all questions in this section in the spaces provided. Write using blue or black pen.Where an answer box has a unit printed in it, give your answer in that unit.You should take the value of g to be 10 m s–2.Whereanswerboxesareprovided,writeyourfinalanswerinthebox.In questions worth more than 1 mark, appropriate working should be shown.Unless otherwise indicated, the diagrams in this book are not drawn to scale.


SECTION A – Core studies – continuedTURN OVER

c. CalculatethetensioninthecableconnectingthetugboatandBarge1. 2 marks

N

d. CalculatetheimpulsegivenbyBarge1toBarge2inthefirst10sofmotion.Includeanappropriateunit. 2 marks


SECTION A – Core studies – continued

Question 2 (6 marks)Somestudentsconductexperimentsinvolvingtwotrolleys,TrolleyAandTrolleyB.TrolleyAhasamassof2.0kgandTrolleyBhasamassof1.0kg.

a. Intheirfirstexperiment,TrolleyAismovingtotherightat3.0ms–1 and Trolley B is moving totherightat1.0ms–1,asshowninFigure2.Thetrolleyscollide,butdonotsticktogetherinthecollision.Afterthecollision,TrolleyAismovingtotherightat2.0ms–1.

2.0 kg 1.0 kg3.0 m s–1 1.0 m s–1

A B

Figure 2

CalculatethespeedofTrolleyBafterthecollision.Showyourworking. 3 marks

m s–1

b. Intheirsecondexperiment,TrolleyAismovingtotherightat4.0ms–1 and Trolley B is stationary,asshowninFigure3.Thetrolleyscollideand,afterthiscollision,TrolleyAismovingtotherightat2.0ms–1andTrolleyBismovingtotherightat4.0ms–1.

2.0 kg 1.0 kg4.0 m s–1

A B

Figure 3

i. Explaintheterms‘elastic’and‘inelastic’asappliedtocollisions. 1 mark

ii. Determinewhetherthiscollisioniselasticorinelastic. 2 marks



Question 3 (7marks)An amusement park has a car ride consisting of vertical partial circular tracks, as shown in Figure4a.Thetrackisarrangedsothatthecarremainsuprightatboththetopandbottompositions.Thetrackhasaradiusof12.0manditslowestpointispointP.

12.0 m

12.0 mT

P24 m s–1

Figure 4a Figure 4b

a. OnthediagraminFigure4b,drawlabelledarrowsshowingalloftheforcesonthecaratpointPanddrawtheresultantforcewithadottedarrowlabelledFR. 3 marks

b. AtpointP,thecarismovingat24ms–1.

Calculatetheforceofthecarseatonapassengerofmass50kgasthecarpassespointP.Showyourworking. 2 marks

N

c. Emily says that if the car moves at the correct speed at the top, point T, a person can feel weightlessatthatpoint.

Rogersaysthisisnonsense;apersoncanonlyfeelweightlessindeepspace,wherethereisnogravity.

Whoiscorrect?Justifyyouranswer. 2 marks



Question 4 (7marks)A spring has a spring constant, k, of 20 N m–1.PointPshowstheunstretchedlengthofthespring.

Δx(cm)

0

20

40

60

80

P

Q

RS

Figure 5a Figure 5bnot to scale

m

a. Amass,m,ishungfromthespring. Itextendsthespring0.60mtopointR,asshowninFigure5a.

Calculatethemassofm. 2 marks

kg

b. ThemassisnowraisedtopointQandreleased,sothatitoscillatesbetweenpointsQandS,asshowninFigure5b.

CalculatethechangeinspringpotentialenergyinmovingfrompointQtopointS.Showyourworking. 2 marks

J



c. Eight graphs, A.–H.,areshownbelow.

0 10 20 30 40 50 60 70 80x (cm)

energyA.

0 10 20 30 40 50 60 70 80x (cm)

energyB.

0 10 20 30 40 50 60 70 80x (cm)

energyC.

0 10 20 30 40 50 60 70 80x (cm)

energyD.

0 10 20 30 40 50 60 70 80x (cm)

energyE.

0 10 20 30 40 50 60 70 80x (cm)

energyF.

0 10 20 30 40 50 60 70 80x (cm)

energyG.

0 10 20 30 40 50 60 70 80x (cm)

energyH.

In the boxes provided below, indicate which graph(s) (A.–H.) would show the total energy, the gravitational potential energy (take the zero of gravitational potential energy at the lowest point,S),thekineticenergyandthespringpotentialenergyasthemassoscillates. 3 marks

Total energy

Gravitational potential energy

Kinetic energy

Spring potential energy



Question 5 (6 marks)Anarchershootsarrowsatatarget5.0maway.

a. Initially,thearchershootsthearrowshorizontally,asshowninFigure6.Thearrowleavesthebow1.0mabovetheground.Assumethearrowstravelwithaconstanthorizontalcomponentof 12 m s–1.

1.0 m

Figure 6

Thearcherfindsthatthearrowsarehittingthegroundratherthanreachingthetarget.

Calculatehowfarhorizontallyfromthelaunchingpointthearrowswillhittheground. 2 marks

m

b. Thetargetismoved.Inordertohitthetargetatthisnewposition,thearcherfindsthatheneedstoshootthearrowsatanangleof30°abovethehorizontal,asshowninFigure7.Thearrows still leave the bow at 12 m s–1.

1.0 m 1.0 m

Figure 7

Calculatethehorizontaldistancetothetarget.Showyourworking. 2 marks

m

11 2017 PHYSICS EXAM (NHT)


c. A bow can be treated as a simple spring, as shown in Figure 8a. The force–distance graph of the bow is shown in Figure 8b. The x-axis shows the distance the archer pulls back the bow string.

An arrow has a mass of 0.03 kg.

00

20

40

60

80

100

120

140

160

0.1 0.2 0.3pull back (m)

force (N)

Figure 8a Figure 8b

The bow is pulled back 0.20 m and released.

Calculate the speed at which the arrow leaves the bow. 2 marks

m s–1



Question 6 (6 marks)ThedwarfplanetPlutohasanorbitalperiodof248Earthyears(1Earthyear=365days).Assumetheorbitisexactlycircular.Themassofthesunis2.0×1030kg.G=6.67×10–11 N m2 kg–2

a. CalculatePluto’sorbitalperiod. 1 mark

s

b. CalculatePluto’sdistancefromthecentreofthesun.Ignoretheradiusofthesun.Showyourworking. 3 marks

m

c. Anastronautcanthrowaball5.0mintotheaironEarth. TheaccelerationduetogravityonPlutois0.62ms–2.

EstimatehowhightheastronautcouldthrowtheballonPluto.Showyourworking. 2 marks

m



CONTINUES OVER PAgE



Area of study – Electronics and photonics

Question 7 (8 marks)StudentssetupthecircuitshowninFigure9.

18 V

60 Ω

30 Ω

20 Ω 20 Ω

Figure 9

a. Calculatethepotentialdifferenceacrossthe30Ωresistor. 2 marks

V

b. Calculatethecurrentflowingthroughthe60Ωresistor. 2 marks

A



The students modify the circuit, changing the resistor and battery values, and replacing one resistor withadiode,asshowninFigure10.

17 V

80 Ω

80 Ω40 Ω

Figure 10

ThecharacteristicsofthediodeareshowninFigure11.

–3 –2 –1 0 1 2 3

50

I (mA)

V (volts)

Figure 11

Thestudentsnotethatthecurrentthroughthediodeisgreaterthan50mA.

c. Calculatethepotentialdifferenceacrossoneofthe80Ωresistors. 2 marks

V

d. Calculatethecurrentflowingthroughoneofthe80Ωresistors. 2 marks

A



Question 8 (4 marks) Thecurrent-voltagecharacteristicsofalight-emittingdiode(LED)areshowninFigure12.

I (mA)

–1.0 0 1.0 2.0 3.0

10

20

30

V (volts)

Figure 12

StudentsconnecttheLEDintoacircuit,asshowninFigure13.Theresistorhasavalueof500Ω.

A

R = 500 Ω

Figure 13

Thestudentsobservethatthepowerdissipatedintheresistoris0.050W.



a. Calculatethevoltageofthebatteryinthecircuit.Showyourworking. 3 marks

V

b. Thebatteryisnowreversed.

CalculatethepotentialdifferenceacrosstheLED. 1 mark

V



Question 9 (2 marks)Studentsconstructacircuittodemonstrateanaspectofmodulation,asshowninFigure14.ThereisaslidingcontactonresistorR1.ThisvariestheresistanceofR1inthecircuit.

R2

R1

receivercircuit

Figure 14

TheslidingcontactismovedbackwardsandforwardssothattheresistanceofR1 in the circuit varies with time,asshowninFigure15.

time (s)0 0.5 1.0 1.5 2.0 2.5

resistance of R1in the circuit

(arbitrary units)

Figure 15

Ontheaxesprovidedbelow,drawthevariationinthebrightnessoftheLEDovertime.AssumetheLEDisalwaysconducting.

time (s)0 0.5 1.0 1.5 2.0 2.5

brightness of LED(arbitrary units)



Question 10 (4 marks)Studentsareusingalight-dependentresistor(LDR),abatteryandaresistortobuildacontrolcircuit.ThecharacteristicsoftheLDRareshowninFigure16.

light intensity (lux)0 5 10 15 20

543210

RLDR (kΩ)

Figure 16

ThestudentstesttheLDRusingthecircuitshowninFigure17.

to controlcircuitR

LDR10 V

A

Figure 17

Atalightintensityof5lux,theyfindthereisavoltageof6.0VacrosstheresistorR.

a. CalculatethesizeoftheresistorR.Showyourworking. 2 marks

kΩ

b. Thecontrolcircuitswitchesoffanoutdoorlampwhenthevoltageacrosstheresistoris7.5Vormore.

Atwhatlightintensitywouldthelampswitchon?Showyourworking. 2 marks

lux



Question 11 (4 marks)Avoltageamplifierhastheinput-outputcharacteristicsshowninFigure18.

–15 –10 –5 0 5 10 15

–4

–2

2

4

Vin (mV)

Vout (V)

Figure 18

a. Calculatethegainoftheamplifierinitslinearregion. 2 marks

b. Forasinusoidaloutputsignalfreeofclipping,calculatethemaximumRMSvoltagethatcanbeappliedtotheinputoftheamplifier. 2 marks

mV



CONTINUES OVER PAgE



Area of study – Electric power

Question 12 (5 marks)Figure19ashowstwosolenoidsandFigure19bshowsasmallmagneticcompass.Thesamecurrentflowsthroughbothsolenoids.IgnoreEarth’smagneticfield.

N

SX

Figure 19a Figure 19b

UsethedirectionsA.–F. below to answer part a. and part b.

N

S

A.

S

N

B.

N S S N

C. D.

NS

E.

NS

F.

a. ThesmallmagneticcompassisplacedatpointXinFigure19a.

WhichofthedirectionsA.–F.bestshowshowthecompasswillpoint?Giveareasonforyouranswer. 2 marks

23 2017 PHYSICS EXAM (NHT)


b. A wire carrying a current, I, vertically upwards is placed midway between the two solenoids, as shown in Figure 20.

I

Figure 20

Which of the options A.–G. below best shows the direction of the electromagnetic force on the wire? Explain your answer. 3 marksA. upwardsB. downwardsC. into pageD. out of pageE. leftF. rightG. force will be zero



Question 13 (6 marks)Students build a simple electric motor consisting of a single coil and a split-ring commutator, as showninFigure21.Themagneticfieldbetweenthepolepiecesisaconstant0.02T.

N SX

W Z

0.50 A

split-ring commutatoraxis of rotation

Y5.0 cm

Figure 21

a. CalculatethemagnitudeoftheforceonthesideWX. 2 marks

N

b. Willthecoilrotateinaclockwiseoranticlockwisedirectionasseenbyanobserveratthesplit-ringcommutator?Explainyouranswer. 2 marks



c. Explaintheroleofthesplit-ringcommutatorintheoperationoftheelectricmotor. 2 marks



Question 14 (11 marks)Asquareloopofside10cmisallowedtomovehorizontallythrougharegionofamagneticfield.ThisisshowninFigure22.Assumethemagneticfieldisuniformanddoesnotextendbeyondthelimitsofthemagnets.

AX Y

N

Sleadingedge

Figure 22

ThearrangementisshownasviewedfromaboveinFigure23a.

A

10 cm

10 cm

30 cm 30 cm10 cmP Q R S

P0

0

Q R S

P Q R S

x

x

flux(ΦB)

emf

Figure 23a

Figure 23b

Figure 23c

X Y

a. OnthegraphprovidedinFigure23b,sketchthemagnitudeofthefluxthreadingtheloopastheloopmoveswithitsleadingedgemovingfromPtoS. 2 marks

b. OnthegraphprovidedinFigure23c,sketchtheinducedemfastheloopmoveswithitsleadingedgemovingfromPtoS. 2 marks



c. Makingreferencetoanyrelevantphysicallaw,determinewhetherthecurrentwillflowfrom XtoYorfromYtoXthroughthemeterAastheloopmovesintothemagneticfield.Explain youranswer. 4marks

d. Themagneticfieldhasauniformvalueof2.0×10–3Tandtheloophasaresistanceof2.0Ω.Thelooptakes0.50stomoveintothemagneticfield.

CalculatetheaveragecurrentinthemeterAastheloopmovesintothemagneticfield.Showyourworking. 3 marks

A



Question 15 (9 marks) Afarmerwishestorunapowerlinefromhishousetoacowshedtooperatealargecoolroom.The voltage available at the house is 240 VRMSAC.Thepowerlinewireshaveatotalresistanceof6.0Ω.Thecoolroommachineryhasaconstantresistanceof10Ωandisdesignedtooperateon 240 VRMSAC.TheinstallationisshowninFigure24.

cowshed6.0 Ω total

6.0 Ω total

house

240 VRMS AC

240 VRMS AC

power line wires to coolroom

coolroommachinery (10 Ω)

coolroommachinery (10 Ω)

Figure 24

a. Calculatethepowerofthecoolroommachinerywhenitisoperatingcorrectlyasdesigned. 2 marks

W

b. CalculatethepowerusedbythecoolroommachineryinthearrangementshowninFigure24.Showyourworking. 4 marks

W



c. Thefarmersaysthecoolroommachineryisnotoperatingcorrectly.Anelectriciansaysthisisduetolossofvoltageinthepowerlinewiresandthetransmissionvoltageneedstobehigher.Theelectricianhastwotransformersavailable:astep-downof20:1andastep-upof1:20.

In the space provided below, sketch how these transformers should be installed in the systemtoimprovetheoperationofthecoolroommachineryinthecowshed.

Usethesymbolsbelowinyourdiagram. 3 marks

step-down step-up coolroommachinery

20:1 1:20



Question 16 (5 marks)Astudentconstructsasimplealternator.ThealternatorisshowninFigure25a.Itsoutputsignal,asseenonanoscilloscope,isshowninFigure25b.

S N

–8–7–6–5–4–3–2–1012345678

0 10 20 30 40 t (ms)

V (V)

Figure 25a

Figure 25b

a. UsingthegraphinFigure25b,determinethefrequencyoftheoutputsignal.Showyourworking. 2 marks

Hz

b. Thespeedofrotationisnowdoubled.

OnFigure25b,sketchwhatthestudentwillnowseeontheoscilloscope. 3 marks



CONTINUES OVER PAgE



Area of study – Interactions of light and matter

Question 17 (7marks)A teacher uses a microwave set that has wavelength λ=3.0cmtodemonstrateYoung’sexperiment.TheapparatusisshowninFigure26.

S1

S2

double slits

observed intensity

microwavetransmitter

microwave detectorX

Figure 26

a. ThemicrowavedetectorisplacedatpointX(thesecondnodallineoutfromthecentre).Aminimumintensityisobserved.

Estimate the path difference S1X–S2X. 2 marks

cm

b. ExplaintheimportanceofYoung’sexperimentinthedevelopmentofthewavemodeloflight. 3 marks



c. The teacher replaces the double slit with a single slit of width w and measures the width, y cm, ofthediffractionpatternatpointP,asshowninFigure27.

microwavetransmitter slit

P

w microwave detectory

Figure 27

Themicrowavesethastwowavelengthsettings:3.0cmand6.0cm.Theteacherchangesthesettingfrom3.0cmto6.0cm.

Describetheeffectofchangingthewavelengthsettingonthepatternasobserved.Explainyouranswer. 2 marks



Question 18 (11 marks)StudentssetuptheapparatusshowninFigure28tostudythephotoelectriceffect.Theapparatusconsistsofalightsource,afilterandaphotocell(ametalemittingplateonwhichlightfallsandacollectingelectrode/collector,allenclosedinavacuumtube).

VA

light sourcefilter

photocell

variablesource

collector emitting plate

Figure 28

a. Thestudentsallowlightof500nmtoshineonthephotocell.

Determinetheenergyofeachphotonofthislight. 2 marks

eV

The students then begin the experiment with the collector negative, with respect to the emittingplate.Theygraduallyreducethevoltagetozeroandthenincreaseittopositivevalues.TheymeasurethecurrentinammeterAandplotthegraphasshowninFigure29.

I (µA)

3.02.01.0

1.0

2.0

3.0

0emitting plate tocollector voltage (V)–1.0–2.0–3.0

Figure 29

b. UsingthegraphinFigure29,determinethemaximumkineticenergyoftheemittedphotoelectrons. 1 mark

eV


SECTION A – Core studies – Question 18 – continuedTURN OVER

c. Determinetheworkfunctionofthemetaloftheemittingplate.Showyourworking. 2 marks

eV

d. ExplainwhythegraphinFigure29isaflat,straightlinebeyondV=+1.0V. 2 marks



e. Thestudentsdoubletheintensityofthelight,keepingthefrequencythesame,andplottheresultsonagraph,withtheoriginalcurrentshownasadashedline.

Whichoneofthefollowinggraphs(A.–D.)willtheynowobtain? 1mark

I (µA)

3.02.01.01.0

2.03.0

0emitting plate tocollector voltage (V)

emitting plate tocollector voltage (V)



–1.0–2.0–3.0

I (µA)

3.02.01.01.0

2.03.0

0–1.0–2.0–3.0

I (µA)

3.02.01.01.0

2.03.0

0–1.0–2.0–3.0

I (µA)

3.02.01.01.0

2.03.0

0–1.0–2.0–3.0

A.

B.

C.

D.

f. Explain your answer to part e.,withreferencetotheparticlemodelandthewavemodeloflight. 3 marks



Question 19 (5 marks)Studentsuseapieceofapparatustostudyelectrondiffraction.Theapparatusconsistsofanevacuated tube, with an electron gun at one end, a crystal in front of the electron gun and a screen attheotherend.TheapparatusisshowninFigure30.

crystaldiffraction patternon screen

evacuated tube

electron gun

Figure 30

Theelectronsareacceleratedbyavoltagetoaspeedof2.0×107 m s–1.Themassofanelectronis9.1×10–31kg.

a. CalculatethedeBrogliewavelengthoftheseelectrons.Showyourworking. 2 marks

nm

b. X-rayscanproducethesamediffractionpatternaselectrons.

CalculatetheenergythattheX-raysmusthavetoproducethesamediffractionpatternaselectronswithadeBrogliewavelengthof0.10nm.Showyourworking. 3 marks

eV



Question 20 (3 marks)Figure31showstheenergylevelsforasodiumatom.

n = 5

n = 4

n = 3

n = 2

ground state n = 1

3.75 eV

ionisation

Figure 31not to scale

3.66 eV

3.19 eV

2.11 eV

0

A sodium atom is excited to the n=3state.

Listallofthephotonenergies,ineV,thatcouldbeemittedasthesodiumatomreturnstothegroundstate.


END OF SECTION ATURN OVER

Question 21 (4 marks)DeBrogliesuggestedthatthequantisedenergystatesofatomscouldbeexplainedintermsofelectronsformingstandingwaves.

Describehowtheconceptofstandingwavescanhelpexplainthequantisedenergystatesofanatom.Youshouldincludeadiagram.


SECTION B – Detailed study – continued

Detailed study – Materials and their use in structures

Use the following information to answer Questions 1–6.Anengineeristestingsamplesofdifferentcablematerials,A,BandC.Eachsampleshetestshasacross-sectionalareaof4.0×10–3 m2andalengthof0.50m.The results from each test were recorded and, from these, a stress-strain graph for each material was constructed,asshowninFigure1.

400

350

300

250

200stress

(MPa)

50

00 4 8 12 16

strain (×10–3)20 24 28 32

100

150

fracture pointelastic limit

A

B

C

Key

Figure 1

Question 1Whichmaterialshowselasticbehaviouroverthelargestrangeofstrainvalues?A. AB. BC. CD. cannot be determined from the data

SECTION B

Instructions for Section BAnswer allquestionsinpencilontheanswersheetprovidedformultiple-choicequestions.Choosetheresponsethatiscorrectforthequestion.Acorrectanswerscores2;anincorrectanswerscores0.Marks will notbedeductedforincorrectanswers.Nomarkswillbegivenifmorethanoneansweriscompletedforanyquestion.Unlessotherwiseindicated,thediagramsinthisbookarenot drawntoscale.


SECTION B – Detailed study – continuedTURN OVER

Question 2Whichmaterialisthemostductile?A. AB. BC. CD. cannot be determined from the data

Question 3Basedonthedata,whichoneofthefollowingbestgivesYoung’smodulusforMaterialC?A. 17PaB. 1.7×104PaC. 1.3×1010PaD. 1.7×1010Pa

Question 4Whichmaterialisthetoughest?A. AB. BC. CD. cannot be determined from the data

Question 5WhichoneofthefollowingbestgivestheforcerequiredtobreakthesampleofMaterialB?A. 300 NB. 1.2×106 NC. 3.0×108 ND. 1.2×1010 N

Question 6ThesampleofMaterialChasaforceof2.0×105Nappliedtoit.Whichoneofthefollowingbestgivestheextension(stretchfromoriginallength)ofthesample?A. 5.0×10–4 mB. 1.5×10–3 mC. 1.5×10–2 mD. 0.50m

2017 PHYSICS EXAM (NHT) 42

SECTION B – Detailed study – continued

Question 7A cable is wound around a drum. The drum is held stationary at the left end by a brake and a load is hanging from the right end, as shown in Figure 2.

brake

load

Figure 2

Which one of the following best describes the stress in the drum?A. shearB. elasticC. ductileD. tension

Use the following information to answer Questions 8–10.A lookout platform is constructed using a 5 tonne (5000 kg) unreinforced concrete beam supported by a cable, as shown in Figure 3. Ignore the mass of the cable. The link at O is flexible to allow for a small amount of rotation as the cable expands and contracts.At a particular time, a group of people with a combined mass of 500 kg stand at point Q, the very end of the platform.

8.0 m10.0 m

30°

cable

R

P

Q

beam forminglookout platformO

Figure 3

Question 8Which one of the following best gives the torque about O due to the beam alone?A. 2.5 × 103 N mB. 5.0 × 103 N mC. 2.5 × 105 N mD. 4.0 × 105 N m


END OF QUESTION AND ANSWER BOOK

Question 9WhichoneofthefollowingbestgivesthetensioninthecableRP?A. 5.0×103 NB. 5.0×104 NC. 6.3×104 ND. 7.5×104 N

Question 10Engineersfindtheunreinforcedconcretebeamissaggingdangerouslyinsomeplaces.Toovercomethis,theyreplaceitwithareinforcedconcretebeam.Whichoneofthefollowinggivesthebestplacementforsteelreinforcingrodsintheconcretebeam?

A.

B.

C.

D.

Question 11Figure4showsthedesignforatrussbridgethatistobeconstructedusingsteelgirders.

P

R

T

Q S

Figure 4

Roadauthoritieswantthemassofthebridgetobereduced.Anengineerhassuggestedreplacingsomeofthesteelgirderswithsteelcables.Whichofthefollowingbestshowsthesteelgirdersthatcouldsafelybereplacedwithsteelcables?A. QRandSRB. QR,SRandQSC. PQ,QSandSTD. PQandST

Victorian Certificate of Education 2017

© VICTORIAN CURRICULUM AND ASSESSMENT AUTHORITY 2017

PHYSICS

Written examination

Monday 5 June 2017 Reading time: 10.00 am to 10.15 am (15 minutes) Writing time: 10.15 am to 12.45 pm (2 hours 30 minutes)

FORMULA SHEET

Instructions

• A question and answer book is provided with this formula sheet.

Students are NOT permitted to bring mobile phones and/or any other unauthorised electronic devices into the examination room.

PHYSICS – FORMULA SHEET 2

1 velocity; acceleration v xt

a vt

= =∆∆

∆∆

;

2 equations for constant acceleration

v u at

x ut at

v u ax

x v u t

= +

= +

= +

= +( )

12

12

2

2 2 2

3 Newton’s second law ΣF = ma

4 circular motion a vr

rT

= =2 2

24π

5 Hooke’s law F = – k x

6 elastic potential energy 12

2kx

7 gravitational potential energy near the surface of Earth mgh

8 kinetic energy 12

2mv

9 Newton’s law of universal gravitation F G M Mr

= 1 22

10 gravitational field g G Mr

= 2

11 acceleration due to gravity at Earth’s surface g = 10 m s –2

12 voltage; power V = RI P = VI = I2R

13 resistors in series RT = R1 + R2

14 resistors in parallel1 1 1

1 2R R RT= +

15 transformer actionVV

NN

1

2

1

2=

16 AC voltage and current V VRMS peak=12

I IRMS peak=12

17 magnetic force F = I l B

3 PHYSICS – FORMULA SHEET

TURN OVER

18 electromagnetic induction emf: ε = −Nt

∆∆Φ

flux: Φ = BA

19 transmission losses Vdrop = Iline Rline Ploss = I2line Rline

20 mass of the electron me = 9.1 × 10–31 kg

21 charge on the electron e = –1.6 × 10–19 C

22 Planck’s constanth = 6.63 × 10–34 J s

h = 4.14 × 10–15 eV s

23 speed of light c = 3.0 × 108 m s–1

24 photoelectric effect E hf WKmax = −

25 photon energy E = hf

26 photon momentum p h=λ

27 de Broglie wavelength λ =hp

28 speed, frequency and wavelength v = f λ

29 energy transformations for electrons in an electron gun (<100 keV)

12

2mv eV=

30 radius of electron path r mveB

=

31 magnetic force on a moving electron F = evB

32 electric field between charged plates E Vd

=

33 stress σ =FA

34 strain ε =∆LL

35 Young’s modulus E =stressstrain

36 universal gravitational constant G = 6.67 × 10–11 N m2 kg–2

37 mass of Earth ME = 5.98 × 1024 kg

38 radius of Earth RE = 6.37 × 106 m

PHYSICS – FORMULA SHEET 4

39 mass of the electron me = 9.1 × 10–31 kg

40 charge on the electron e = –1.6 × 10–19 C

41 speed of light c = 3.0 × 108 m s–1

Prefixes/Units

p = pico = 10–12

n = nano = 10–9

μ = micro = 10–6

m = milli = 10–3

k = kilo = 103

M = mega = 106

G = giga = 109

t = tonne = 103 kg

END OF FORMULA SHEET

Documents

2017 Physics-nht Written examination - Pages