Mark Scheme (Results) Summer Pearson Edexcel GCSE 9-1 In Physics (1PHZ_1PH) Paper 05

Transcription

1 Mark Scheme (Results) Summer 2017 Pearson Edexcel GCSE 9-1 In Physics (1PHZ_1PH) Paper 05

2 Edexcel and BTEC Qualifications Edexcel and BTEC qualifications are awarded by Pearson, the UK s largest awarding body. We provide a wide range of qualifications including academic, vocational, occupational and specific programmes for employers. For further information visit our qualifications websites at or Alternatively, you can get in touch with us using the details on our contact us page at Pearson: helping people progress, everywhere Pearson aspires to be the world s leading learning company. Our aim is to help everyone progress in their lives through education. We believe in every kind of learning, for all kinds of people, wherever they are in the world. We ve been involved in education for over 150 years, and by working across 70 countries, in 100 languages, we have built an international reputation for our commitment to high standards and raising achievement through innovation in education. Find out more about how we can help you and your students at: Summer 2017 Publications Code 1PHZ_1PH_01_1705_MS All the material in this publication is copyright Pearson Education Ltd 2017

3 General Marking Guidance All candidates must receive the same treatment. Examiners must mark the first candidate in exactly the same way as they mark the last. Mark schemes should be applied positively. Candidates must be rewarded for what they have shown they can do rather than penalised for omissions. Examiners should mark according to the mark scheme not according to their perception of where the grade boundaries may lie. There is no ceiling on achievement. All marks on the mark scheme should be used appropriately. All the marks on the mark scheme are designed to be awarded. Examiners should always award full marks if deserved, i.e. if the answer matches the mark scheme. Examiners should also be prepared to award zero marks if the candidate s response is not worthy of credit according to the mark scheme. Where some judgement is required, mark schemes will provide the principles by which marks will be awarded and exemplification may be limited. When examiners are in doubt regarding the application of the mark scheme to a candidate s response, the team leader must be consulted. Crossed out work should be marked UNLESS the candidate has replaced it with an alternative response.

4 1 (a) An answer that that combines the following to provide a logical description of the method (4) Responses may be seen on diagram. measure angle of incidence (1) measure angle of refraction (1) allow calculate for measure in context ( measure angles insufficient must be specified) measure angle from incident ray measure angle from refracted ray measure angle(s) to the normal (1) repeat for different angle(s) (of incidence) (1) accept (reference to drawing path of) refracted ray (inside block) / emergent ray / ray under or leaving block allow to dotted line for normal

5 1 (b) An explanation that combines identification via a judgement (1 mark) to reach a conclusion via justification (1 mark): (2) anomalous result / it is at (angle of incidence) 40 o (1) (because) it is further away from the curve of best fit than the other results (1) the 4 th cross the one in the middle. may be identified on the graph does not follow same pattern as the others / not in line etc. explains the cause of the error e.g. misreading protractor suggests a plausible correct result such as 40( o ),25( o ) ignore points at i = 40( o ) and 50( o ) are the same

6 Mark 2(a)(i) rearrangement (1) Rearrangement and substitution may be in either order (m=) substitution (1) (m=). evaluation (1) 2500(kg) (m=).. ignore unit conversion until evaluation POT (power of ten) error, e.g. 2.5 (kg) award 2 marks (3) award full marks for correct numerical answer without working If no other marks scored, award one mark for a clear conversion of units

7 Mark 2(a)(ii) correctly identifies data points from the graph to calculate areas (1) use of distance = area under graph (1) substitution (1) both 7 and 13 seen (distance) = (23-16) 13 2 evaluation rounded to 2SF (1) 46 (m) (distance) = accept 45 (m) (= 45.5) award full marks for correct numerical answer without working (4) 91 scores 2 marks (incorrect area calculation using distance x time)

8 Mark 2(b) An answer that combines the following points to provide a logical description of the method (3) mention of a relevant distance and time (1) use of speed = distance / time (1) one way of maximising the accuracy (1) use several lamp posts reference point on car repeat and average in correct context 3 (a) (i) C transverse longitudinal Multiple choice (1) 3 (a) (ii) Substitution (1) (Distance =) 330 x 6.0 Evaluation (1) 2000 (m) award full marks for the correct answer without working 1980(m) 1.98 km 2.0 km (2)

9 3 (b) (i) recall K.E.= ½ m v 2 (1) rearrangement (1) (m =) 2 x K.E. v 2 substitution (1) (m =) 2 x Evaluation (1) = 1200 (kg) award full marks for the correct answer without working rearrangement and substitution in either order Ignore POT until evaluation (4) 3 (b) (ii) Use of efficiency equation (1) evaluation (1) =19 (MJ) award full marks for correct numerical answer without working accept 19.2 (MJ) (2)

10 Mark 4(a)(i) A The submarine is speeding up. (1) Additional guidance Mark 4(a)(ii) An explanation that combines identification (1 mark) and reasoning (1 mark) identify the two forces which are (force of the submarine on the water) and force/push of water on the submarine/propeller (1) (2) these forces are equal and opposite (1) states N s 3 rd law mentions action and reaction ignore balanced forces

11 4(a) (iii) Mark An explanation that combines identification (1 mark) and reasoning (1 mark) states N s 2 nd law (1) (2) The reason that a long time is needed is because of a big change in momentum (1) large momentum if no other marks scored F = ma scores 1 mark OR large mass scores 1 mark Mark 4 (b) Any two advantages such as: nuclear fuel does not contribute to global warming does not use up fossil fuels accept reverse arguments does not produce carbon dioxide / greenhouse gases occupies less space does not involve a supply of air gives less reason to surface/refuel (2) lasts longer ignore cheaper, cleaner, greener, pollutes the sea, more efficient, unqualified safety, renewable

12 4(c) s will be credited according to candidate's deployment of knowledge and understanding of the material in relation to the qualities and skills outlined in the generic mark scheme. The indicative content below is not prescriptive and candidates are not required to include all the material which is indicated as relevant. Additional content included in the response must be scientific and relevant. AO1 (6 marks) Mark Stage 1 (At the beginning) maximum force is applied With zero resistive force(s) And maximum acceleration Stage 2 As the speed increases the increasing resistive force results in a decreasing resultant forward force And a decreasing acceleration So velocity increases at a decreasing rate Stage 3 Eventually thrust = resistive force(s) Then no resultant force forward and no acceleration Submarine continues forward at a constant speed (6) Level Mark Descriptor 0 No rewardable material. Level Demonstrates elements of physics understanding, some of which is inaccurate. Understanding of scientific ideas lacks detail. (AO1) Presents an explanation with some structure and coherence. (AO1) Level Demonstrates physics understanding, which is mostly relevant but may include some inaccuracies. Understanding of scientific ideas is not fully detailed and/or developed. (AO1) Presents an explanation that has a structure which is mostly clear, coherent and logical. (AO1) Level Demonstrates accurate and relevant physics understanding throughout. Understanding of the scientific ideas is detailed and fully developed. (AO1) Presents an explanation that has a well-developed structure which is clear, coherent and logical. (AO1)

13 5 (a) B radio waves Multiple choice (1) 5 (b) (i) Accept any answer between 502 and 510 nm inclusive 1 5 (b) (ii) Substitution (1) frequency = 3.0 x 10 8 / (505 x 10-9 ) Evaluation (1) =5.9 x Unit mark (1) Hz accept answers in range 5.88 x to 5.98 x Accept hertz / s -1 (3) 5 (b) (iii) An answer that combines three points of interpretation/evaluation to provide a logical description (3) Yellow or green or blue detected/seen the best/most sensitive to / highest relative sensitivity (1) Red or orange not detected/not seen (so well)/least sensitive to/lowest relative sensitivity (1) violet or indigo not detected/not seen (so well)/less sensitive to (1) about 500 nm more than 550 nm less than 450 nm (3) 2 max if only wavelength instead of colours

14 5 (c) A comparison that combines a maximum of four out of the following points to provide a reasoned response Q does not ask for wavelengths specifically so colours will do both are sensitive about midrange yellow/green/blue peak at different wavelengths the insect will be better at long(er) wavelengths red end (4) the insect will be much better at detecting shorter wavelengths violet end the insect will be able to detect some wavelengths that humans cannot ultraviolet both are insensitive at longer wavelengths red end. the insect detects a greater range of wavelengths/colours than the human eye humans more sensitive than insects at 510 (nm) accept 490 to 520

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