2018 Physics. Advanced Higher. Finalised Marking Instructions

Size: px

Start display at page:

Download "2018 Physics. Advanced Higher. Finalised Marking Instructions"

Allan Rodgers
5 years ago
Views:

National Qualifications 018 018 Physics Advanced Highe Finalised Making Instuctions Scottish Qualifications Authoity 018 The infomation in this publication may be epoduced to suppot SQA

1 National Qualifications Physics Advanced Highe Finalised Making Instuctions Scottish Qualifications Authoity 018 The infomation in this publication may be epoduced to suppot SQA qualifications only on a noncommecial basis. If it is epoduced, SQA should be clealy acknowledged as the souce. If it is to be used fo any othe pupose, witten pemission must be obtained fom pemissions@sqa.og.uk. Whee the publication includes mateials fom souces othe than SQA (seconday copyight), this mateial should only be epoduced fo the puposes of examination o assessment. If it needs to be epoduced fo any othe pupose it is the cente s esponsibility to obtain the necessay copyight cleaance. SQA s NQ Assessment team may be able to diect you to the seconday souces. These ing instuctions have been pepaed by examination teams fo use by SQA appointed es when ing extenal couse assessments. This publication must not be epoduced fo commecial o tade puposes.

2 Geneal ing pinciples fo Advanced Highe Physics This infomation is povided to help you undestand the geneal pinciples you must apply when ing candidate esponses to questions in the pape. These pinciples must be ead in conjunction with the detailed ing instuctions, which identify the key featues equied in candidate esponses. (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) Maks fo each candidate esponse must always be assigned in line with these geneal ing pinciples and the detailed ing instuctions fo this assessment. Making should always be positive. This means that, fo each candidate esponse, s ae accumulated fo the demonstation of elevant skills, knowledge and undestanding: they ae not deducted fom a maximum on the basis of eos o omissions. If a specific candidate esponse does not seem to be coveed by eithe the pinciples o detailed ing instuctions, and you ae uncetain how to assess it, you must seek guidance fom you team leade. Thee ae no half s awaded. Whee a wong answe to pat of a question is caied fowad and the wong answe is then used coectly in the following pat, the candidate should be given cedit fo the subsequent pat o follow on. Unless a numeical question specifically equies evidence of woking to be shown, full s should be awaded fo a coect final answe (including units if equied) on its own. Cedit should be given whee a diagam o sketch conveys coectly the esponse equied by the question. It will usually equie clea and coect labels (o the use of standad symbols). Maks ae povided fo knowledge of elevant elationships alone, but when a candidate wites down seveal elationships and does not select the coect one to continue with, fo example by substituting values, no can be awaded. Maks should be awaded fo non-standad symbols whee the symbols ae defined and the elationship is coect, o whee the substitution shows that the elationship used is coect. This must be clea and unambiguous. Whee a tiangle type elationship is witten down and then not used o used incoectly, then any fo a elationship should not be awaded. Significant figues Data in question is given to 3 significant figues. Coect final answe is 8 16 J Final answe 8 J o J o J Awad the final. Final answe 8 J o J Do not awad the final Candidates should not be cedited fo a final answe that includes: thee o moe figues too many o two o moe figues too few, ie accept two moe o one fewe page 0

3 (l) The incoect spelling of technical tems should usually be ignoed and candidates should be awaded the elevant, povided that answes can be intepeted and undestood without any doubt as to the meaning. Whee thee is ambiguity, the should not be awaded. Two specific examples of this would be when the candidate uses a tem that might be intepeted as eflection, efaction o diffaction (eg defaction ) o one that might be intepeted as eithe fission o fusion (eg fussion ). (m) Maks ae awaded only fo a valid esponse to the question asked. Fo example, in esponse to questions that ask candidates to: descibe, they must povide a statement o stuctue of chaacteistics and/o featues; detemine o calculate, they must detemine a numbe fom given facts, figues o infomation; estimate, they must detemine an appoximate value fo something; explain, they must elate cause and effect and/o make elationships between things clea; identify, name, give, o state, they need only name o pesent in bief fom; justify, they must give easons to suppot thei suggestions o conclusions, eg this might be by identifying an appopiate elationship and the effect of changing vaiables; pedict, they must suggest what may happen based on available infomation; show that, they must use physics [and mathematics] to pove something eg a given value all steps, including the stated answe, must be shown; suggest, they must apply thei knowledge and undestanding of physics to a new situation. A numbe of esponses ae acceptable: s will be awaded fo any suggestions that ae suppoted by knowledge and undestanding of physics; use you knowledge of physics o aspect of physics to comment on, they must apply thei skills, knowledge and undestanding to espond appopiately to the poblem/situation pesented (fo example by making a statement of pinciple(s) involved and/o a elationship o equation, and applying these to espond to the poblem/situation). They will be ewaded fo the beadth and/o depth of thei conceptual undestanding. page 03

4 (n) Making in calculations Question: The cuent in a esisto is 1 5 ampees when the potential diffeence acoss it is 7 5 volts. Calculate the esistance of the esisto. (3 s) Candidate answe Mak + Comment 1. V = IR 1 : fomula 7 5 = 1 5R 1 : substitution R = 5 0 Ω 1 : coect answe. 5 0 Ω 3 s: coect answe s: unit missing Ω 0 s: no evidence, wong answe 5. Ω 0 s: no woking o final answe 6. V 75 R 40 I 15 s: aithmetic eo V 7. R 40 1 : fomula only I V 8. R 1 : fomula only I V 75 R I 15 V 75 R 40 I 15 V 15 R 50 I 75 V 75 R 50 I 15 I 75 R 50 V 15 s: fomula & subs, no final answe s: fomula & subs, wong answe 1 : fomula but wong substitution 1 : fomula but wong substitution 0 s: wong fomula 14. V=IR s: fomula & subs, aithmetic eo 7 5 = 1 5 R R = 0 Ω 15. V=IR I 15 R 0 V 75 1 : fomula coect but wong eaangement of symbols page 04

5 Detailed ing instuctions fo each question Question 1. (a) v t t dv a t dt a ( ) a ms 3 Accept (b) v t t 3 Accept 0 8, 0 753, Constant of integation s v. dt t t method acceptable s ( 00 ) ( 00 ) 0 3 s 0 75 m 0 page 05

6 . (a) (i) The ca s diection/velocity is changing. 1 OR Unbalanced/centipetal/cental foce acting on the ca v 3 Accept: 7, 6 81, a ( ) 35 a ( ) a 18 a 35 ( ) 6 8 m s a a 68 m s (iii) mv F F 18 F 7 ( N) 3 NOT A STANDARD SHOW QUESTION Appoach calculating minimum adius is acceptable. Since 7 (N)>64(N) OR Thee is insufficient fiction and the ca does not stay on the tack. page 06

7 . (b) (i) (max) ( F( centipetal), W mg) mv v v (max) (max) (max) g mg g mv, SHOW question both elationships equating foces v v v (max) (max) (max) g ms -1 Accept: 3, 5, 54 (iii) The second ca will not lose contact with the tack. A smalle centipetal foce is supplied by a smalle weight. page 07

8 3. (a) t o 0 ( ) 6 ads -1 SHOW question If final answe not shown 1 max (b) 1 3 Accept: 1, 1 7, 1 7 E( k ) I I 6 I 13 kg m (c) (i) 14 O 0 6 ( 14 ) 3 8 ad s - 4 Accept: -4, -3 84, Altenative method: 14 1 o t AND ot t all substitutions coect -38 ad s - T I T 13 ( ) 38 T ( ) 4 9 N m 3 Accept: 5, 4 94, OR consistent with (b), (c)(i) page 08

9 4. (a) (i) ( F F ) centipetal GMm m o T 4 GM 3 T 4 T GM 3 gavitational T 3 SHOW question both elationships equating Altenative method acceptable ( F F ) mv centipetal GMm gavitational v o v T T 4 GM 3 T 4 T GM 3, T 4 GM 3 ( ) 4 ( ) M 11 3 M (kg), 3 Accept:, 1 7,1 74 fo conveting AU to m independent. complete substitution final answe (b) GM 3 OR consistent with (a) v v v 3810 m s Accept 4, 3 79, page 09

10 5. (a) The Schwazschild adius is the distance fom the cente of a mass such that, the escape velocity at that distance would equal the speed of light. 1 Responses in tems of black hole acceptable OR The Schwazschild adius is the distance fom the cente of a mass to the event hoizon. (b) (i) GM 3 Accept: , , ( Schwazchild ) c ( Schwazchild ) 8 ( ) ( Schwazchild ) m (Radius of Sun is m) This is geate than the Schwazschild adius (the Sun is not a black hole.) 1 Thee MUST be a compaison of sola adius with the Sun s Schwazschild adius. (c) s 3 a( 1 e ) ( ) Angula change afte one yea = 4 6 Angula change 0 10 ad 3 OR consistent with (b)(i) Second independent Accept, 03, 035 If 3 14 used, accept 034 page 10

11 6. Demonstates no undestanding 0 s Demonstates limited undestanding 1 Demonstates easonable undestanding. s Demonstates good undestanding 3 s This is an open-ended question. 3 Open-ended question: a vaiety of physics aguments can be used to answe this question. Maks ae awaded on the basis of whethe the answe oveall demonstates no, limited, easonable o good undestanding. 1 : The student has demonstated a limited undestanding of the physics involved. The student has made some statement(s) which is/ae elevant to the situation, showing that at least a little of the physics within the poblem is undestood. s: The student has demonstated a easonable undestanding of the physics involved. The student makes some statement(s) which is/ae elevant to the situation, showing that the poblem is undestood. 3 s: The maximum available would be awaded to a student who has demonstated a good undestanding of the physics involved. The student shows a good compehension of the physics of the situation and has povided a logically coect answe to the question posed. This type of esponse might include a statement of the pinciples involved, a elationship o an equation, and the application of these to espond to the poblem. This does not mean the answe has to be what might be temed an excellent answe o a complete one. page 11

12 7. (a) (i) Neutons ae acceleated. 1 h 3 p m Accept 5 1, 5 140, (iii) The pecise/exact position of a paticle and its momentum cannot both be known at the same instant. 1 OR If the (minimum) uncetainty in the position of a paticle is educed, the uncetainty in the momentum of the paticle will incease (o vice-vesa). (iv) % p 4 px p px h h xminpx o xpx x(min) x m (min) Accept 1 4, 1 363, x min m do not awad final (b) The uncetainty in position will be (too) small. Neutons can be consideed a paticle/cannot be consideed a wave, even on the length scale of the lattice spacing. Accept a de Boglie wavelength agument. A lage uncetainty in p may esult in a lage uncetainty in the de Boglie wavelength. This de Boglie wavelength may not be close to the lattice spacing. Uncetainty in position less than gap between layes acceptable fo both s. page 1

13 8. (a) (i) Main sequence 1 X: helium (nucleus) Z: positon Accept alpha paticle Accept anti-electon Accept He, e +,β + Do not accept Helium atom (b) Sola wind 1 Do not accept cosmic ays. (c) (i) 6 p nv n60 3 n 1 58 ( paticles pe cm ) Coect unit convesions must be made. Accept 1 6, 1 577, (A) (B) (As the paticles ae ejected in all diections they will) spead out (as they get futhe fom the Sun). (The paticles lose kinetic enegy and) gain (gavitational) potential (enegy) (as they move futhe fom the Sun.) OR Wok is done against the Sun s gavitational field (fo the paticles to move away). 1 Accept density deceases with adius/sun acts as a point souce/constant numbe of paticles ove a lage aea. 1 Accept eduction in velocity due to gavitational foce and statement of 1 E mv K Lose speed on its own not sufficient (d) The chaged paticles have a component (of velocity) paallel to the (magnetic) field which moves them fowads in that diection. The component (of velocity) pependicula: to the (magnetic) field causes a cental foce on the chaged paticle OR it moves in a cicle. Independent s page 13

14 9. (a) (i) d SHOW question dt Accept, f o as a 15 t T 5 stating point ad s Final line must appea o max (1 ). x 0 cos( 38t) dx 38 0 sin( 38t) dt d x 38 0 cos( 38t) dt d x 38 x dt (Since the equation is in the fom) a y o a x (, the hoizontal displacement is consistent with SHM). 3 NOT A STANDARD SHOW QUESTION Fist fo BOTH diffeentiations coect Second fo coect substitution of x back into second diffeential (including coect teatment of negatives). Numeical constant may be evaluated without penalty (14 44). Statement egading significance of equation equied fo thid. (iii) v A y v 1 v 0 76m s 3 Accept v (max) A Accept A=0 m o A=-0 m Accept dx 38 0 sin( 38 t) dt as a stating point. Accept 0 8, 0 760, (iv) 1 ( m) v ( m) gh h 98 h 910 m 3 Allow 1 ( m) A ( m) gh as stating point. 1 ( m) y ( m) gh zeo s unless statement that y = A Accept 3, 95, 947 page 14

15 9. (b) The shape of the line should esemble a sinusoidal wave with values eithe all positive o all negative and the minimum vetical displacement consistent. Peak height should show a steady decline with each oscillation / deceasing amplitude, as shown in the gaph in the additional guidance notes. Maks independent page 15

16 10. (a) (i) x 3 Accept 1 7, 1 73, ad (The electic field vectos will be in) opposite (diections at positions P and Q). 1 (b) (i) v f SHOW question 14 6 v Both equation and substitution must 8 1 v 0310 m s be shown. Final line must also be shown. 1 Accept 1 9, 1 931, vm m m 8 m 0310 m F m page 16

17 11. (a) (Division of) amplitude 1 (b) x 0 l x d d d m 4 Fist independent Accept 5, 4 51, (c) Reduces the uncetainty in the value of x o d obtained. OR Reduces the impact/significance of any uncetainty on the value obtained fo x o d. 1 (d) The wie expands/d inceases l x, (and since d inceases) d while l and emain constant, (x deceases). OR Since d inceases and x 1 d, x deceases. page 17

18 1. (a) (i) The bightness (stats at a maximum and) deceases to (a minimum at) 90 o. Response must indicate a gadual change as the analyse otates. The bightness then inceases (fom the minimum back to the maximum at 180 o ). The bightness emains constant (thoughout). 1 (b) (i) n tan i i p tan p Accept 53, 53 06, i p 531 o The polaising sunglasses will act as an analyse/ absob/block (some of) the glae. 1 page 18

19 13. (a) Foce pe unit positive chage (at a point in an electic field) 1 (b) (i) F W F F e tan 4 e= tan 30 4 e= N NOT A STANDARD SHOW QUESTION opposite tan is an acceptable adjacent stating point QQ 1 F ( 10 ) m Accept 0 09, , Accept if 910 used. (iii) Q 5 O consistent with (b) V 4 o Accept : 4000, ( m) 9 V Vtotal V = V total page 19

20 14. (a) 3 B T 1 Accept 9, 9 4, 9 40 (b) (i) q V Accept, 1 51, m B OR consistent with (a) 3 q m ( 9 10 ) 0 8 q m 1510 C kg 11 1 %Uncetainty in B & is doubled 4 Suspend sig fig ule % ( w) % x % y % z q % ( ) ( ) m q 11 1 ( ) C kg m (c) B and 1/ ( and 1/B ) OR 1 Also accept constants coectly included on the axes B and 1/ ( and 1/B) OR I and 1/ ( and 1/I) OR I and 1/ ( and 1/I ) page 0

21 14. (d) Demonstates no undestanding 0 s Demonstates limited undestanding 1 Demonstates easonable undestanding s Demonstates good undestanding. 3 s This is an open-ended question. 3 Open-ended question: a vaiety of physics aguments can be used to answe this question. Maks ae awaded on the basis of whethe the answe oveall demonstates no, limited, easonable o good undestanding. 1 : The student has demonstated a limited undestanding of the physics involved. The student has made some statement(s) which is/ae elevant to the situation, showing that at least a little of the physics within the poblem is undestood. s: The student has demonstated a easonable undestanding of the physics involved. The student makes some statement(s) which is/ae elevant to the situation, showing that the poblem is undestood. 3 s: The maximum available would be awaded to a student who has demonstated a good undestanding of the physics involved. The student shows a good compehension of the physics of the situation and has povided a logically coect answe to the question posed. This type of esponse might include a statement of the pinciples involved, a elationship o an equation, and the application of these to espond to the poblem. This does not mean the answe has to be what might be temed an excellent answe o a complete one. page 1

22 15. (a) t RC R R Accept 6, 6 5, 6 50 (b) t RC t 1 t s 6 SHOW question (c) (i) di L 3 Accept 9 5, 9 543, dt 3 3 di dt di A s dt (Additional) esisto will dissipate enegy. Inducto will stoe enegy (and then delive it to the patient). No enegy loss/dissipation in inducto acceptable fo second. [END OF MARKING INSTRUCTIONS] page

Markscheme May 2017 Calculus Higher level Paper 3

Markscheme May 2017 Calculus Higher level Paper 3 M7/5/MATHL/HP3/ENG/TZ0/SE/M Makscheme May 07 Calculus Highe level Pape 3 pages M7/5/MATHL/HP3/ENG/TZ0/SE/M This makscheme is the popety of the Intenational Baccalaueate and must not be epoduced o distibuted