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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.
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.
5 2017PHYSICSEXAM(NHT)
SECTION A – Core studies – continuedTURN OVER
c. CalculatethetensioninthecableconnectingthetugboatandBarge1. 2 marks
N
d. CalculatetheimpulsegivenbyBarge1toBarge2inthefirst10sofmotion.Includeanappropriateunit. 2 marks
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
7 2017PHYSICSEXAM(NHT)
SECTION A – Core studies – continuedTURN OVER
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.
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
9 2017PHYSICSEXAM(NHT)
SECTION A – Core studies – continuedTURN OVER
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
a. Initially,thearchershootsthearrowshorizontally,asshowninFigure6.Thearrowleavesthebow1.0mabovetheground.Assumethearrowstravelwithaconstanthorizontalcomponentof 12 m s–1.
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)
SECTION A – Core studies – continuedTURN OVER
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
2017PHYSICSEXAM(NHT) 12
SECTION A – Core studies – continued
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
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)
SECTION A – Core studies – continuedTURN OVER
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
2017PHYSICSEXAM(NHT) 24
SECTION A – Core studies – Question 13 – continued
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
25 2017PHYSICSEXAM(NHT)
SECTION A – Core studies – continuedTURN OVER
c. Explaintheroleofthesplit-ringcommutatorintheoperationoftheelectricmotor. 2 marks
2017PHYSICSEXAM(NHT) 26
SECTION A – Core studies – Question 14 – continued
a. OnthegraphprovidedinFigure23b,sketchthemagnitudeofthefluxthreadingtheloopastheloopmoveswithitsleadingedgemovingfromPtoS. 2 marks
b. OnthegraphprovidedinFigure23c,sketchtheinducedemfastheloopmoveswithitsleadingedgemovingfromPtoS. 2 marks
27 2017PHYSICSEXAM(NHT)
SECTION A – Core studies – continuedTURN OVER
c. Makingreferencetoanyrelevantphysicallaw,determinewhetherthecurrentwillflowfrom XtoYorfromYtoXthroughthemeterAastheloopmovesintothemagneticfield.Explain youranswer. 4marks
d. Themagneticfieldhasauniformvalueof2.0×10–3Tandtheloophasaresistanceof2.0Ω.Thelooptakes0.50stomoveintothemagneticfield.
CalculatetheaveragecurrentinthemeterAastheloopmovesintothemagneticfield.Showyourworking. 3 marks
A
2017PHYSICSEXAM(NHT) 28
SECTION A – Core studies – Question 15 – continued
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
29 2017PHYSICSEXAM(NHT)
SECTION A – Core studies – continuedTURN OVER
c. Thefarmersaysthecoolroommachineryisnotoperatingcorrectly.Anelectriciansaysthisisduetolossofvoltageinthepowerlinewiresandthetransmissionvoltageneedstobehigher.Theelectricianhastwotransformersavailable:astep-downof20:1andastep-upof1:20.
In the space provided below, sketch how these transformers should be installed in the systemtoimprovetheoperationofthecoolroommachineryinthecowshed.
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
35 2017PHYSICSEXAM(NHT)
SECTION A – Core studies – Question 18 – continuedTURN OVER
c. Determinetheworkfunctionofthemetaloftheemittingplate.Showyourworking. 2 marks
eV
d. ExplainwhythegraphinFigure29isaflat,straightlinebeyondV=+1.0V. 2 marks
2017PHYSICSEXAM(NHT) 36
SECTION A – Core studies – continued
e. Thestudentsdoubletheintensityofthelight,keepingthefrequencythesame,andplottheresultsonagraph,withtheoriginalcurrentshownasadashedline.
f. Explain your answer to part e.,withreferencetotheparticlemodelandthewavemodeloflight. 3 marks
37 2017PHYSICSEXAM(NHT)
SECTION A – Core studies – continuedTURN OVER
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
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.
41 2017PHYSICSEXAM(NHT)
SECTION B – Detailed study – continuedTURN OVER
Question 2Whichmaterialisthemostductile?A. AB. BC. CD. cannot be determined from the data
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
43 2017PHYSICSEXAM(NHT)
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