Page 13 19. A circuit is set up as shown. 12 V 4·0 Ω A The resistance of the variable resistor is increased and corresponding readings on the ammeter are recorded. Resistance (Ω) 2·0 4·0 6·0 8·0 Current (A) 2·0 1·5 1·2 1·0 These results show that as the resistance of the variable resistor increases the power dissipated in the variable resistor A increases B decreases C remains constant D decreases and then increases E increases and then decreases. 20. A 20 μF capacitor is connected to a 12 V d.c. supply. The maximum charge stored on the capacitor is A 1·4 × 10−3 C B 2·4 × 10−4 C C 1·2 × 10−4 C D 1·7 × 10−6 C E 6·0 × 10−7 C. [END OF SECTION 1. NOW ATTEMPT THE QUESTIONS IN SECTION 2 OF YOUR QUESTION AND ANSWER BOOKLET] Page 14 [BLANK PAGE] DO NOT WRITE ON THIS PAGE Page 15 [BLANK PAGE] DO NOT WRITE ON THIS PAGE Page 16 [BLANK PAGE] DO NOT WRITE ON THIS PAGE H FOR OFFICIAL USE Fill in these boxes and read what is printed below. Number of seat Town © Mark Full name of centre Forename(s) Surname Scottish candidate number Date of birth Year Day Month National Qualications 2016 Total marks — 130 SECTION 1 — 20 marks Attempt ALL questions. Instructions for the completion of Section 1 are given on Page 02. SECTION 2 — 110 marks Attempt ALL questions. Reference may be made to the Data Sheet on Page 02 of the question paper X757/76/02 and to the Relationships Sheet X757/76/11. Care should be taken to give an appropriate number of significant figures in the final answers to calculations. Write your answers clearly in the spaces provided in this booklet. Additional space for answers and rough work is provided at the end of this booklet. If you use this space you must clearly identify the question number you are attempting. Any rough work must be written in this booklet. You should score through your rough work when you have written your final copy. Use blue or black ink. Before leaving the examination room you must give this booklet to the Invigilator; if you do not, you may lose all the marks for this paper. X757/76/01 TUESDAY, 24 MAY 9:00 AM – 11:30 AM A/PB Physics Section 1 — Answer Grid and Section 2 Page 02 SECTION 1 — 20 marks The questions for Section 1 are contained in the question paper X757/76/02. Read these and record your answers on the answer grid on Page 03 opposite. Use blue or black ink. Do NOT use gel pens or pencil. 1. The answer to each question is either A, B, C, D or E. Decide what your answer is, then fill in the appropriate bubble (see sample question below). 2. There is only one correct answer to each question. 3. Any rough work must be written in the additional space for answers and rough work at the end of this booklet. Sample Question The energy unit measured by the electricity meter in your home is the: A ampere B kilowatt-hour C watt D coulomb E volt. The correct answer is B — kilowatt-hour. The answer B bubble has been clearly filled in (see below). A B C D E Changing an answer If you decide to change your answer, cancel your first answer by putting a cross through it (see below) and fill in the answer you want. The answer below has been changed to D. A B C D E If you then decide to change back to an answer you have already scored out, put a tick (3) to the right of the answer you want, as shown below: A B C D E or A B C D E Page 03 A B C D E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 SECTION 1 — Answer Grid [Turn over Page 04 [BLANK PAGE] do not write on this page Page 05 [Turn over for SECTION 2 do not write on this page Page 06 MARKS DO NOT WRITE IN THIS MARGIN SECTION 2 — 110 marks Attempt ALL questions 1. 9·1 m s−1 24° P Q sh not to scale An athlete takes part in a long jump competition. The athlete takes off from point P with an initial velocity of 9·1 m s−1 at an angle of 24º to the horizontal and lands at point Q. (a) Calculate: (i) the vertical component of the initial velocity of the athlete; Space for working and answer (ii) the horizontal component of the initial velocity of the athlete. Space for working and answer 1 1 Page 07 MARKS DO NOT WRITE IN THIS MARGIN 1. (continued) (b) Show that the time taken for the athlete to travel from P to Q is 0·76 s. Space for working and answer (c) Calculate the horizontal displacement sh between points P and Q. Space for working and answer (d) The graph shows how the horizontal displacement of the athlete varies with time for this jump when air resistance is ignored. displacement (m) time (s) sh 0 Add a line to the graph to show how the horizontal displacement of the athlete varies with time when air resistance is taken into account. (An additional graph, if required can be found on Page 38) 2 3 2 [Turn over Page 08 MARKS DO NOT WRITE IN THIS MARGIN 2. A student uses the apparatus shown to investigate the force of friction between the wheels of a toy car and a carpet. toy car ramp h d carpet not to scale The toy car is released from rest, from a height h. It then travels down the ramp and along the carpet before coming to rest. The student measures the distance d that the car travels along the carpet. The student repeats the procedure several times and records the following measurements and uncertainties. Mass of car, m : (0·20 ± 0·01) kg Height, h : (0·40 ± 0·005) m Distance, d : 1·31 m 1·40 m 1·38 m 1·41 m 1·35 m (a) (i) Calculate the mean distance d travelled by the car. Space for working and answer (ii) Calculate the approximate random uncertainty in this value. Space for working and answer 1 2 Page 09 MARKS DO NOT WRITE IN THIS MARGIN 2. (continued) (b) Determine which of the quantities; mass m, height h or mean distance d, has the largest percentage uncertainty. You must justify your answer by calculation. Space for working and answer (c) (i) Calculate the potential energy of the toy car at height h. An uncertainty in this value is not required. Space for working and answer [Turn over 4 3 Page 10 MARKS DO NOT WRITE IN THIS MARGIN 2. (c) (continued) (ii) Calculate the average force of friction acting between the toy car and carpet, as the car comes to rest. An uncertainty in this value is not required. Space for working and answer (iii) State one assumption you have made in (c) (ii). 3 1 Page 11 [Turn over for next question do not write on this page Page 12 MArKS DO NOT WRITE IN THIS MARGIN 3. The following apparatus is set up to investigate the law of conservation of linear momentum. computer m s−1 v1 v2 m s−1 light gate 1 light gate 2 vehicle Y vehicle X frictionless track In one experiment, vehicle X is travelling to the right along the track and vehicle Y is travelling to the left along the track. The vehicles collide and stick together. The computer displays the speeds of each vehicle before the collision. The following data are recorded: Mass of vehicle X = 0·85 kg Mass of vehicle Y = 0·25 kg Speed of vehicle X before the collision = 0·55 m s−1 Speed of vehicle Y before the collision = 0·30 m s−1 (a) State the law of conservation of linear momentum. (b) Calculate the velocity of the vehicles immediately after the collision. Space for working and answer 1 3 Page 13 MARKS DO NOT WRITE IN THIS MARGIN 3. (continued) (c) Show by calculation that the collision is inelastic. Space for working and answer [Turn over 4 Page 14 MARKS DO NOT WRITE IN THIS MARGIN 4. Two physics students are in an airport building on their way to visit CERN. (a) The first student steps onto a moving walkway, which is travelling at 0·83 m s−1 relative to the building. This student walks along the walkway at a speed of 1·20 m s−1 relative to the walkway. The second student walks alongside the walkway at a speed of 1·80 m s−1 relative to the building. moving walkway direction of travel walkway Determine the speed of the first student relative to the second student. Space for working and answer 2 Page 15 MARKS DO NOT WRITE IN THIS MARGIN 4. (continued) (b) On the plane, the students discuss the possibility of travelling at relativistic speeds. (i) The students consider the plane travelling at 0·8c relative to a stationary observer. The plane emits a beam of light towards the observer. State the speed of the emitted light as measured by the observer. Justify your answer. (ii) According to the manufacturer, the length of the plane is 71 m. Calculate the length of the plane travelling at 0·8c as measured by the stationary observer. Space for working and answer (iii) One of the students states that the clocks on board the plane will run slower when the plane is travelling at relativistic speeds. Explain whether or not this statement is correct. [Turn over 2 3 1