2004 Physics. Advanced Higher. Finalised Marking Instructions

Transcription

1 004 Physics Advanced Higher Finalised Marking Instructions

2 Detailed Marking Instructions AH Physics 00. Numerical Marking (a) (c) (d) (e) The fine divisions of marks shown in the marking scheme may be recorded within the body of the script beside the candidate s answer. If such marks are shown they must total to the mark in the inner margin. Negative marks or marks to be subtracted should not be shown. An inverted vee may be used instead. The number recorded should always be the marks being awarded. The number out of which a mark is scored SHOULD NEVER BE SHOWN AS A DENOMINATOR. (½ mark will always mean one half mark and never out of.) Where square ruled paper is enclosed inside answer books it should be clearly indicated that this item has been considered. Marks awarded should be transferred to the script booklet inner margin and marked G. Fractional marks, if awarded to individual questions, should be recorded in the grid, but the total script mark must be rounded up to the next whole number when transferred to the box at the top of the script.. Other Marking Symbols which may be used TICK correct point as detailed in scheme, includes data entry SCORE THROUGH any part of answer which is wrong. (For a block of wrong answer indicate zero marks.) INVERTED VEE a point omitted which has led to a loss of marks. WAVY LINE under an answer worth marks which is wrong only because a wrong answer has been carried forward from a previous part. G Reference to a graph on separate paper. You MUST show a mark on the graph paper and the SAME mark on the script. WP Marks not awarded because an apparently correct answer was due to the use of wrong physics. ARITH Candidate has made an arithmetic mistake. Page

3 . General Instructions (Refer to National Qualifications Booklet) (a) (c) (d) (e) (f) (g) (h) No marks are allowed for a description of the wrong experiment or one which would not work. Full marks should be given for information conveyed correctly by a sketch. Surplus answers: where a number of reasons, examples etc are asked for and a candidate gives more the required number then wrong answers may be treated as negative and cancel out part of the previous answer. Full marks should be given for a correct answer to a numerical problem even if the steps are not shown explicitly. The part marks shown in the scheme are for use in marking partially correct answers. Where mark is shown for the final answer to a numerical problem ½ mark may be deducted for an incorrect unit. Where a final answer to a numerical problem is given in the form -6 instead of 0-6 then deduct ½ mark. Deduct ½ mark if an answer is wrong because of an arithmetic slip. No marks should be awarded in a part question after the application of a wrong physics principle (wrong formula, wrong substitution) unless specifically allowed for in the marking scheme. In certain situations, a wrong answer to a part of a question can be carried forward within that part of the question. This would incur no further penalty provided that it is used correctly. Such situations are indicated by a horizontal dotted line in the marking instructions. Wrong answers can always be carried forward to the next part of a question, over a solid line without penalty. (i) (j) (k) (l) ½ mark should be awarded for selecting a formula. Where a triangle type relationship is written down and then not used or used incorrectly then any partial ½ mark for a formula should not be awarded. In numerical calculations, if the correct answer is given then converted wrongly in the last line to another multiple/submultiple of the correct unit then deduct ½ mark. Significant figures. Data in question is given to significant figures. Correct final answer is 8 6J. Final answer 8 J or 8 58J or 8 576J No penalty. Final answer 8J or 8 576J Deduct ½ mark. Candidates should be penalised for a final answer that includes three or more figures too many or two or more figures too few. ie accept two higher and one lower Page

4 (m) Squaring Error E K ½ mv ½ 4 4J (-½, ARITH) E K ½ mv ½ 4 4J (½, formula) Incorrect substitution. The General Marking Instructions booklet should be brought to the markers' meeting. Page 4

5 004 Physics Advanced Higher. (a) m m m o v ( 0 ) v ms v 8 0 m/ s o m o v c for c or or 9 0 Could be implied in equation 5 v 09 c m m m o v c 9 0 ( 09 c) m kg 0 ( ) c m 0 kg for substitution 8 ms m s v 7 0 / E mc 0 E c E E 9 0 J for substitution must calculate a value of m - if m 9 0 kg taken max ( ) for equation Page 5

6 004 Physics Advanced Higher. (a) (i) (gravitational) Ep rotational Ek (linear/translational) Ek } Ek alone 9 rotational Ek E p stated - no penalty I Mr Formula given I 0 (005) I ( kg m ) Total I kg m (c) w 0 rad s - Ek Ep Iw mgh } h h m h 0 9 m (d) (i) the (5N) force of spring is not great enough to provide the required centripetal force. Any force outwards WP0 F mw r 5 ( 0 - ) w (0 0 - ) w 4666 If m 4 max ( ) for formula w 04 w 04 rad s - Page 6

7 004 Physics Advanced Higher. (a) w o 600 π 60 0 π (rad s ) unit in question w w α o t 0 0π α 0 α OR deceleration α rad s } w 0π w o 0 Wrong physics max ½ for formula Accept /π rad s (c) w w o + αθ 0 (0 π) θ θ (rad) θ π rev θ 50 (rev) Can use θ w o t + ½αt (d) T I α T T T Nm ( )Nm (e) I less - α greater - I less, time less only must mention α for full marks time less - Page 7

8 004 Physics Advanced Higher 4. (a) GMEm mw r r π w T correct maths T π r GM E Must start by equating forces or accelerations π r v T 6 (i) r T π given GM E T π 6 4 ( ) Data marks T s ( 86 min) given v wr both formulae ms d v t m Accept m Page 8

9 004 Physics Advanced Higher 5. (a) vertically 8 Tension m Weight Pulling force Weight + Force Tension F 7 0 F N (i) restoring force proportional to displacement F kx F a 4ms m 05 carry forward 5(a) (iii) amplitude 0 06 m (or 60 mm) (c) (i) the acceleration dy a w y dt when y 0 06 m, a 4 ms - 4 () w 006 carry forward 5b(iii) w ( 70) w 8 66 f w π Hz Accept Hz Page 9

10 004 Physics Advanced Higher 6. (a) (i) the force per unit positive (charge placed at a point in the field) Must state both unit and positive 7 F qe work in moving charge between plates Fd qed also So qv qv qed V Ed or V E d } V E d alone (0) (i) lines to plates + sphere (judgement) sphere lines lines No lines to sphere (0) sphere lines arrows as shown in (i) + (iii) E O Page 0

11 004 Physics Advanced Higher 7. (a) F 4πε 0 QQ r or equivalent statement in words spheres touching bring insulator near Not touching - WP - (0) or equivalent diagrams separate spheres + (c) (i) F QQ 4πε r 0 5 q 0 4π (40 0 ) (½ data ) 8 q q 0 C given V Qq 4 πε r 0 V V x y ( 070( V) ) ( 4 6( V) ) 9 0 4π π V V + V x y 700V subtraction No subtraction - max(½) (iii) charges displaced towards centre Page

12 004 Physics Advanced Higher 7. (continued) (d) (i) F W T α T α W F OR components method T cos α T sin α W F (diagram ) T F + W 5 5 ( 0 ) + ( ) F tanα W see part (½) T T 47 0 N then substitution to find T (i) N Accept N ½ α tan α 5 tan 0 ( ) ( α 7 ) F W Accept α v F T Sin W T cos Accept 0. rad ½ Page

13 004 Physics Advanced Higher 8. (a) mv qvb r 6 for equating correct maths mv qb s t s πr v t πr v π mv v qb πm t (no v) qb Accept πm T qb Where T period (c) m 9 0 t π 9 5 qb π ( ) t( ) 6 0 s data marks Page

14 004 Physics Advanced Higher 9. (a) V 6V level Curve incorrect - (O) 5 (O) curve t/s V IR 0 Ω 4V ε across L 6V 4 6V di ε L dt di dt ε L } di ( + ) 6 ((+)0 9As dt 4 if 0 9As max() Page 4

15 004 Physics Advanced Higher 0. (a) At wire µ I B πr 0 9 F BI L µ 0I IL πr F µ 0II hence L πr (i) F µ 0II (given) L πr 7 4π π Nm ½ apart ½ (iii) B 7 µ I 4π πr π T If 4 m used max - Formula direction B same 4 total B 7 0 T direction upwards direction independent (c) F BILsinθ } F BI sinθ L F sin60 L 0 08Nm Sin 0 used max for formula if 60 rad used F L Nm (-½) Arith Page 5

16 004 Physics Advanced Higher. (a) (i) by comparison with standard 8 x y Asinπ ft λ π f f 9(09)Hz π 0 5 λ 56 λ λ m (i) x m x φ π λ φ π φ 0 48 (rad) v fλ 9 4 7(ms ) carry forward a(i), d t 0 040(48)s v 4 7 accept 0 04s Also 0 04s if λ 56m (c) y Asin(t 05) x where A < 8 bracketed term smaller amplitude bracket term with + Page 6

17 004 Physics Advanced Higher. (a) (i) the (electric part of the) waves vibrate or oscillate in the same plane 6 the picture will get poorer (or disappear) Accept suddenly disappears (i) sin ip n sinr } but ip + r 90 r 90 i p sin ip so n sin (90 ip ) sin ip n tan ip cosip (given) Must be sequential 90 shown in proof n perspex tan i p i p } 0 98 rad 56 Page 7

18 004 Physics Advanced Higher. (a) d x 05 0 (6 0 0) λ D λ m 0 missed WP max WP max for formula % uncertainty in d 00. 8% 05 in x % 6 0 WP ( max) 0 0 in D %. 5 % in λ ( + 05) 8 59 okay to include 8 6% (c) increase D use a travelling microscope increases x + reduces uncertainty in x to measure x OR measure more fringes reduces scale reading reduces % uncertainty in x uncertainty (d) division of wavefront [END OF MARKING INSTRUCTIONS] Page 8