MARKSCHEME SPECIMEN PAPER

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1 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M MARKSCHEME SPECIMEN PAPER PHYSICS Higher Level Paper 0 pages

2 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M General Marking Instructions Assistant Examiners (AEs) will be contacted by their team leader (TL) through Scoris, by or telephone if through Scoris or by , please reply to confirm that you have downloaded the markscheme from IBIS. The purpose of this initial contact is to allow AEs to raise any queries they have regarding the markscheme and its interpretation. AEs should contact their team leader through Scoris or by at any time if they have any problems/queries regarding marking. For any queries regarding the use of Scoris, please contact If you have any queries on administration please contact: Richard Pearce Subject Operations IB Cardiff Peterson House Malthouse Avenue Cardiff Gate Cardiff CF 8GL GREAT BRITAIN Tel: +(44) Fax: +(44) richard.pearce@ibo.org

3 . Follow the markscheme provided, award only whole marks and mark only in RED. SPEC/4/PHYSI/HP/ENG/TZ0/XX/M. Make sure that the question you are about to mark is highlighted in the mark panel on the right-hand side of the screen.. Where a mark is awarded, a tick/check () must be placed in the text at the precise point where it becomes clear that the candidate deserves the mark. One tick to be shown for each mark awarded. 4. Sometimes, careful consideration is required to decide whether or not to award a mark. In these cases use Scoris annotations to support your decision. You are encouraged to write comments where it helps clarity, especially for re-marking purposes. Use a text box for these additional comments. It should be remembered that the script may be returned to the candidate. 5. Personal codes/notations are unacceptable. 6. Where an answer to a part question is worth no marks but the candidate has attempted the part question, use the ZERO annotation to award zero marks. Where a candidate has not attempted the part question, use the SEEN annotation to show you have looked at the question. Scoris will apply NR once you click complete. 7. If a candidate has attempted more than one option in Section B, mark all the answers. Scoris will only award the highest mark or marks in line with the rubric. 8. Ensure that you have viewed every page including any additional sheets. Please ensure that you stamp SEEN on any additional pages that are blank or where the candidate has crossed out his/her work. 9. There is no need to stamp an annotation when a candidate has not chosen an option in Section B. Scoris will apply NR once you click complete. 0. Mark positively. Give candidates credit for what they have achieved and for what they have got correct, rather than penalizing them for what they have got wrong. However, a mark should not be awarded where there is contradiction within an answer. Make a comment to this effect using a text box or the CON stamp.

4 Subject Details: Physics HL Paper Markscheme Mark Allocation 4 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M Candidates are required to answer ALL questions in Section A [5 marks] and all questions from ONE option in Section B [0 marks]. Maximum total [45 marks]. Markscheme format example: 4 b ii the displacement and acceleration Accept force for acceleration. are in opposite directions. Each row in the Question column relates to the smallest subpart of the question.. The maximum mark for each question subpart is indicated in the Total column.. Each marking point in the Answers column is shown by means of a tick () at the end of the marking point. 4. A question subpart may have more marking points than the total allows. This will be indicated by max written after the mark in the Total column. The related rubric, if necessary, will be outlined in the Notes column. 5. An alternative wording is indicated in the Answers column by a slash (/). Either wording can be accepted. 6. An alternative answer is indicated in the Answers column by on the line between the alternatives. Either answer can be accepted. 7. Words in brackets in the Answers column are not necessary to gain the mark. 8. Words that are underlined are essential for the mark. 9. The order of marking points does not have to be as in the Answers column, unless stated otherwise in the Notes column. 0. If the candidate s answer has the same meaning or can be clearly interpreted as being of equivalent significance, detail and validity as that in the Answers column then award the mark. Where this point is considered to be particularly relevant in a question it is emphasized by OWTTE (or words to that effect) in the Notes column.. Remember that many candidates are writing in a second language. Effective communication is more important than grammatical accuracy.. Occasionally, a part of a question may require an answer that is required for subsequent marking points. If an error is made in the first marking point then it should be penalized. However, if the incorrect answer is used correctly in subsequent marking points then follow through marks should be awarded. When marking, indicate this by adding ECF (error carried forward) on the script. ECF acceptable will be displayed in the Notes column.. Do not penalize candidates for errors in units or significant figures, unless it is specifically referred to in the Notes column.

5 5 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M SECTION A. a i a 0 ms a ii 44 6 bmax 0.70(ms C ) bmin 0.50(m s C ) b (ms C ) a iii b 0.6( 0.) (ms C ) Allow 0.59 ( 0.0 ). b i 0 550( C) 0.6 b ii temperature is unphysical there is no temperature below 7 C this temperature cannot be right it appears that the linear fit model cannot be extrapolated far from 0C

6 6 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M. a the estimated percentage uncertainty in g is [ ] % Accept. %. b use more than one height obtain g from a suitable graph of height h versus t g is twice the gradient use a smaller ball to reduce air resistance use much larger height repeat many times to get an average of time. a the actual specific heat capacity will be less than calculated value more thermal energy is transferred to the calorimeter and contents than accounted for b metal may not have been heated uniformly metal may not all be at 00 C energy was lost to air during the transfer energy may have been lost to the air through the calorimeter water may not be at uniform temperature Allow h versus t or h versus t or logh logt. Analysis of g must fit quoted graph. Do not allow a bald answer. max

7 7 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M SECTION B Option A Relativity 4. a Maxwell s equations implied a speed of light independent of its source in Newtonian mechanics, speed of light depends on velocity of source Einstein trusted Maxwell s equations Einstein modified Newtonian mechanics b i magnetic b ii if a force exists in one inertial frame a force must exist in any other inertial frame cannot be magnetic because the proton is at rest in S Accept discussion in terms of acceleration as equivalent to force. Accept an answer in terms of electric field. 5. a i (s) c a ii v c vx t t c c c (s)

8 8 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M (Question 5 continued) a iii 8 6 xct b i (m) x xvt c 700(m) c ct B ct 0 0 F rocket frame x x Earth frame starting points at B and F ending at the same point on the ct axis correct slope at 45 degrees Judge by eye.

9 9 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M (Question 5 continued) b ii ct ct B 0 0 lines through B and F parallel to x-axis to see that B happened first b iii vx c [900] t t 0 c c 6 t (s) c solving for u correct substitution correct answer of 0.6c F rocket frame x x Earth frame

10 0 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M 6. a pc E mc [ ] b energy: E E 070(MeV) X Y momentum: EX EY 060(MeV) solving to get EY 5(MeV) 7. a i impossible to distinguish effects of gravity from effects of acceleration frame accelerating in outer space with acceleration a is equivalent to frame at rest in gravitational field with g a frame freely falling in gravitational field is equivalent to inertial frame in outer space a ii version with accelerating frame: observer is moving relative to source and so light experiences Doppler shift motion is away from source and so frequency is reduced frame is equivalent to frame at rest in a gravitational field version with freely falling frame: light received by observer in freely falling frame is blueshifted because of Doppler effect but frame is equivalent to inertial frame so frequency cannot change so rising light suffers gravitational redshift to offset the Doppler blueshift b.5.4(s)

11 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M Option B Engineering physics 8. a a R a TR MR R mg T ma 4 add equations/eliminate tension to get mg ma Ma b i 49.8 a (ms ) as v (m s ) mgh mv I mgh v mv I R v.4 (m s ) 4 8 Award [] for a bald correct answer.

12 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M (Question 8 continued) b ii a Award [] for a bald correct answer. rate of change of L is I I R 9. a a 49.8 MR 60.0 R (N m) rate of change of L is torque on axle 49.8 TR (N m) c P (W) 8 maximum is at B and so TB (K) 5 b i W pv 5.00 [8.0.0] 0 W.0 0 (J) b ii U pv (J) b iii Q U W Award [] for a bald correct answer. Award [] for a bald correct answer (J) Award [] for a bald correct answer.

13 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M (Question 9 continued) c Q 90 Award [ max] for omitted minus sign. S T 400 Award [] for a bald correct answer. S.48.5(J K ) d Award [] for a bald correct answer. e 7500 e 0. e greater 0. a smooth flow non-turbulent flow flow with low Reynolds number b i reference to Av constant area of a flowtube decreases above the foil b ii realization that height plays no role ie. v p v p p p 0.95 [64 5 ] 66.(Pa) L [ p p ] A66..0.(kN) OWTTE Award [ max] for an answer of 7 N. Award [] for a bald correct answer.

14 4 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M. a 4 Q 4 Q b i the amplitude will increase b ii the phase will approach negative relative to the driving force

15 5 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M Option C Imaging. a i the image would be formed at the focal point of the concave mirror at a distance of 9.50 m from the centre of the concave mirror since the object distance is very large 9.50 i ( D ) u D o Do 4 Di u 0.00(m) a ii the object distance is [ ] 0.9(m) Ignore incorrect sign. so the magnification is the diameter of this image is then (m) a iii angle:.mm 0.6 rad 98.0mm 0.6 magnification: b i with parabolic mirrors the problem of spherical aberration is eliminated b ii no chromatic aberration easier/cheaper to make large mirrors than large lenses easier to support and so can be large max less absorption in glass

16 6 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M (Question continued) c a multitude of sources of EM radiation other than visible light have been discovered comparison of optical and non-optical images can be made thus vastly increasing our understanding of what exists in the universe. a i a ii u f v v D M u fe M a iii 0.mm 60(nm) 80 b power loss (4.66. )8.5(dB).85 p 0 0 power 0.7(mW)

17 7 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M 4. a i sharpness is a measure of how easy it is to see edges of different organs or different types of tissue in an image a ii use as point-like a source as possible reduce backscatter of photons by metal strips placed along direction of incident X-rays use of computer software to detect and enhance edges b i they will be absorbed doing damage without contributing to forming the image b ii at 50 kev absorption coefficient is 0.0cm Accept transmitted intensity fraction is e 67% c i forces protons to make a spin transition c ii allows determination of the point from which the photons are emitted c iii the proton spin relaxation time depends on the type of tissue at the point where the radiation is emitted d no harmful ionizing radiation can better distinguish between different parts of the soft tissue

18 8 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M Option D Astrophysics 5. a helium b i 7.80 Award [] for a bald correct answer. d d 6. 0 m d 000 pc b ii no, the distance is too great for the parallax angle to be measured accurately even from an orbiting telescope b iii.5 M 0 M M M c i estimates of temperatures for star as K and Sun as 6000 K 4 4R R R 4 R c ii line starting at correct position [T 7500K, L 0] and extending into red giants ending at white dwarfs c iii equilibrium between gravitational pressure and electron degeneracy pressure provided final mass is below the Chandrasekhar limit/less than.4m Award [] for a bald correct answer. Accept answers in the range of.9 to..

19 9 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M 6. a i the universe is expanding and so wavelengths like all distances are being Must mention redshift in alternative answer. stretched out wavelength increasing hence the Doppler redshift is being observed a ii v 8 4 Award [] for a bald correct answer. z v (km s ) c 4 v 4.70 d 660(Mpc) H 7 b i gravity is pulling back on the galaxies b ii distant supernovae appeared less bright than expected indicating that they were further away than expected 7. a the binding energy per nucleon curve peaks at mass number of about 60 producing heavier elements with fusion is no longer energetically possible b absorption of neutrons by nuclei in a slow process in stars ending at the production of bismuth in a fast process in supernovae ending with the very heaviest isotopes beyond bismuth

20 0 SPEC/4/PHYSI/HP/ENG/TZ0/XX/M 8. a the universe has structure structures only develop if there are fluctuations/differences in density/ differences in temperature which is what the anisotropies in CMB show b R present t graph as shown does not have to start at the origin c i the curve becomes flat c ii the curve can be used to estimate the mass of the galaxy this mass is greater than the estimate of the mass of the galaxy based on the amount of light radiated

SPEC/4/PHYSI/SP3/ENG/TZ0/XX. Candidate session number PHYSICS PAPER 3. Examination code SPECIMEN PAPER. 1 hour INSTRUCTIONS TO CANDIDATES

SPEC/4/PHYSI/SP3/ENG/TZ0/XX. Candidate session number PHYSICS PAPER 3. Examination code SPECIMEN PAPER. 1 hour INSTRUCTIONS TO CANDIDATES SPEC/4/PHYSI/SP3/ENG/TZ0/XX PHYSICS STANDARD LEVEL PAPER 3 SPECIMEN PAPER Candidate session number Examination code 1 hour INSTRUCTIONS TO CANDIDATES Write your session number in the boxes above. Do not