DHS 2023 JC1 Promos Physics (Paper 2)

1 © DHS 2023 9749/02 [Turn over Name: Index Number: Class: DUNMAN HIGH SCHOOL Promotional Examination Year 5 H2 PHYSICS Paper 2 Structured Questions 9749/02 29 September 2023 1 hour 55 minutes READ THESE INSTRUCTIONS FIRST Write your class, index number and name at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the question paper. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Paper 1 MCQ 15 Paper 2 1 11 2 10 3 9 4 7 5 8 6 10 7 20 s.f. -1 Total 90 This document consists of 19 printed pages and 3 blank pages.

2 © DHS 2023 9749/02 [Turn over Data speed of light in free space, c = 3.00 × 108 m s−1 permeability of free space, o = 4 × 10−7 H m−1 permittivity of free space, o = 8.85 × 10−12 F m−1 = (1/(36)) × 10−9 F m−1 elementary charge, e = 1.60 × 10−19 C the Planck constant, h = 6.63 × 10−34 J s unified atomic mass constant, u = 1.66 × 10−27 kg rest mass of electron, me = 9.11 × 10−31 kg rest mass of proton, mp = 1.67 × 10−27 kg molar gas constant R = 8.31 J K−1 mol−1 the Avogadro constant, NA = 6.02 × 1023 mol−1 the Boltzmann constant, k = 1.38 × 10−23 J K−1 gravitational constant, G = 6.67 × 10−11 N m2 kg−2 acceleration of free fall, g = 9.81 m s−2

3 © DHS 2023 9749/02 [Turn over Formulae uniformly accelerated motion, s = ut + 1 2 at2 v2 = u2 + 2as work done on/by a gas, W = pV hydrostatic pressure, p = gh gravitational potential,  = −Gm/r temperature, T/K = T/oC + 273.15 pressure of an ideal gas, p = 21 3 Nm cV  mean translational kinetic energy of an ideal gas molecule, E = kT2 3 displacement of particle in s.h.m., x = x0 sin t velocity of particle in s.h.m., v = v0 cos t =  22 xxo − electric current, I = Anvq resistors in series, R = R1 + R2 + . . . resistors in parallel, 1/R = 1/R1 + 1/R2 + . . . electric potential, V = r Q o4 alternating current / voltage, x = x0 sin t magnetic flux density due to a long straight wire, B = 0 2 d I  magnetic flux denxity due to a flat circular coil, B = 0 2 N r I magnetic flux density due to a long solenoid, B = 0nI radioactive decay, x = x0 exp(−t) decay constant,  = 1 2 ln2 t

4 Answer all the questions. 1 An experiment to determine the acceleration of free fall g is conducted by projecting a stone with speed u at an angle  to the horizontal. The horizontal distance R travelled by the stone when it returns to the level of projection is measured. Air resistance is negligible. (a) In determining the speed of the stone, a student defines speed as “distance travelled per second”. Explain why this definition is incorrect. …………............…………………………………………………….…………………………… …………............…………………………………………………….…………………………… …………............…………………………………………………….……………………….. [2] (b) By expressing the time of flight of the stone T in terms of g, u and , show that R is given by the expression 22 sin cosuR g = . [3]

5 © DHS 2023 9749/02 [Turn over (c) The expression in (b) can be written as 2 sin2uR g = . The experiment is conducted to obtain the maximum range R0. State and explain the value of  to obtain R0. ............…………………………………………………….………….……………………..…… ……............……………………….………………………………….……………………… [2] (d) The values of u and R0 are 45.36 km h −1 and 16.3 m, with the respective percentage uncertainties of 3% and 4%. Calculate the value of g and present the answer together with its uncertainty. g = ...................  ..................... m s−2 [4] [Total: 11]

6 © DHS 2023 9749/02 [Turn over 2 Statistics for road traffic accidents are sometimes interpreted as showing that many occur because of speeding or tiredness of the driver. As a result, some countries have introduced laws to limit the speed at which vehicles may travel and the length of time a person may drive without rest. Fig. 2.1 To enforce these laws, some types of vehicles are fitted with tachographs. A tachograph records, on a circular chart, amongst other information, the times at which the vehicle is being driven, together with its speed. One such chart from a lorry tachograph is illustrated in Fig. 2.1. The time of day, using the 24 -hour clock, is shown on the inner scale. Each concentric circle represents a speed measured in kilometres per hour (km h −1). For example, at time 12.15, the lorry was travelling at 40 km h−1.

7 © DHS 2023 9749/02 [Turn over (a) Use Fig. 2.1 to determine (i) the speed of the lorry at 11.30, speed = ........................................ km h−1 [1] (ii) the length of time for which the lorry was not moving between 08.00 and mid -day (12.00). length of time = ........................................ hours [1] (b) Suggest what evidence is provided between the times 08.00 and 13.00 on Fig. 2.1 for (i) a device on the lorry which limits its maximum speed, ............................................................................................................................. [1] (ii) the lorry being in a congested area with heavy traffic between 12.45 and 13.00. ................................................. ........................................................................... [1] (c) Fig. 2.2 shows data for a particular journey. time of day activity 16.00 – 18.00 resting 18.00 accelerates to 40 km h−1 18.00 – 18.30 continues at 40 km h−1 18.30 accelerates to 65 km h−1 18.30 – 19.10 continues at 65 km h−1 19.10 stops Fig. 2.2 On Fig. 2.1, draw the trace which would be produced for this journey. [2]

8 © DHS 2023 9749/02 [Turn over (d) The tachograph chart is one form of speed-time graph. Use Fig. 2.1 to estimate the distance travelled by the lorry between 12.00 and 13.00. distance = ........................................ km [2] (e) When the tachograph is switched off, the chart stops rotating and the speed recorded is the maximum for the chart. (i) Use Fig. 2.1 to determine the time at which the tachograph was switched off. time = ........................................ [1] (ii) Suggest why, when the tachograph is switched off, it is desirable for the speed recorded to be the maximum, rather than zero. ............…………………………………………………….…………………………..…… ……............…………………………………………………….……………………… [1] [Total: 10]

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10 © DHS 2023 9749/02 [Turn over 3 (a) Define the moment of a force. …………............…………………………………………………….…………………………… …………............…………………………………………………….……………………….. [1] (b) Fig. 3.1 shows a type of balance that is used for measuring mass. A rigid rod is pivoted about a point 6.2 cm from the centre of a pan which is attached to one end. The object being measured is placed on the centre of this pan. A spring, attached to the rod 1.8 cm from the pivot, is hung at its other end from a fixed point P. The spring obeys Hooke’s law over the full range of operation of the balance. A pointer, on the other side of the pivot, is set against a millimeter scale which is a distance 52.6 cm from the pivot.