RVHS H2 Physics P2 QP

River Valley High School Page 1 of 24 H2 Physics 9749 2025 JC 2 Preliminary Examinations RIVER VALLEY HIGH SCHOOL JC 2 PRELIMINARY EXAMINATIONS H2 PHYSICS 9749 / 2 PAPER 2 18 SEPTEMBER 2025 2 HOURS CANDIDATE NAME CENTRE NUMBER S INDEX NUMBER CLASS 2 4 J INSTRUCTIONS TO CANDIDATES DO NOT OPEN THIS BOOKLET UNTIL YOU ARE TOLD TO DO SO. Read these notes carefully. Write your name, centre number, index number and class in the spaces at the top of this page and on all work you hand in. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected where appropriate. Candidates answer on the Question Paper. No Additional Materials are required. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. FOR EXAMINERS’ USE Paper 2 1 / 7 2 / 9 3 / 8 4 / 12 5 / 8 6 / 9 7 / 6 8 / 8 9 /13 Deduction Paper 2 / 80 This document consists of 23 printed pages and 1 blank page.

River Valley High School Page 2 of 24 H2 Physics 9749 2025 JC 2 Preliminary Examinations Data speed of light in free space, c = 3.00  108 m s–1 permeability of free space, 0 = 4   10–7 H m–1 permittivity of free space, 0 = 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

River Valley High School Page 3 of 24 H2 Physics 9749 2025 JC 2 Preliminary Examinations Formulae uniformly accelerated motion 2 2 1 atuts += 22 2v u as=+ work done on / by a gas W p V= hydrostatic pressure p gh= gravitational potential  = − GM / r temperature T / K = T / C + 273.15 pressure of an ideal gas = 2 3 1 cV Nmp mean translational kinetic energy of an ideal gas molecule kTE 2 3= displacement of particle in s.h.m., x = x0 sin t velocity of particle in s.h.m., v = v0 cos t = )( 22 0 xx − electric current, I = Anvq resistors in series, 12R R R= + + resistors in parallel, 121/ 1/ 1/R R R= + + electric potential, r QV 04= alternating current/voltage, x = x0 sin t magnetic flux density due to a long straight wire, dB   2 0I= magnetic flux density due to a flat circular coil, r NB 2 0 I= magnetic flux density due to a long solenoid, InB 0= radioactive decay, x = x0 exp (−t) decay constant, 2 1 2ln t=

River Valley High School Page 4 of 24 H2 Physics 9749 2025 JC 2 Preliminary Examinations Answer all the questions in the space provided. 1 (a) The kinetic theory of gases is based on some simplifying assumptions. Molecules of the gas are assumed to behave as hard elastic identical spheres. State the assumption about ideal gas molecules based on (i) the nature of their movement, …………..…………………………………………………………………………. ……..………………………………………………………………………... [1] (ii) their volume. …………..…………………………………………………………………………. ……..………………………………………………………………………... [1] (b) The pressure of an ideal gas is given by where N is the number of gas molecules m is the mass of a gas molecule V is the volume of the gas < c 2 > is the mean square speed of the molecules (i) Explain the significance of the “ 1 3 ” in the equation. …………..…………………………………………………………………………. …..…………………………………………………………………………... [1] = 2 3 1 cV Nmp

River Valley High School Page 5 of 24 H2 Physics 9749 2025 JC 2 Preliminary Examinations (ii) Density of nitrogen gas is found to be 1.25 kg m−3 at 0 C and 101 kPa. Assuming nitrogen gas behaves like an ideal gas, determine its root-mean- square speed. root-mean-square speed = ………………….. m s−1 [2] (iii) Use your answer in (b)(ii) to determine the root-mean-square speed of the nitrogen gas at 127 C. root-mean-square speed = ………………….. m s−1 [2]

River Valley High School Page 6 of 24 H2 Physics 9749 2025 JC 2 Preliminary Examinations 2 (a) Define simple harmonic motion. ………………..…………………………………………………………………………… ………………..…………………………………………………………………………… ….…………………………………………………………………………...……… [1] (b) Calculate the gain in potential energy when a mass of 150 g is raised vertically through 1.0 mm. gain in potential energy = ………………….. J [2] (c) A simple pendulum consists of a light inextensible string and a bob of mass 150 g attached. The variation of the potential energy Vp with the horizontal displacement of the bob x is shown in Fig. 2.1. Fig. 2.1

River Valley High School Page 7 of 24 H2 Physics 9749 2025 JC 2 Preliminary Examinations To set the pendulum into oscillation, the bob is displaced sideways (keeping the string taut) until its centre of mass is raised vertically through 1.0 mm and then released. Using your answer in (b), sketch labelled graphs on the axis of Fig. 2.1 to show the variation, as the pendulum oscillates ideally, of x with (i) the total energy. Label it TE. [1] (ii) the kinetic energy. Label it KE. [2] (d) By reference to Fig. 2.1, or otherwise, write down the amplitude of oscillation of the pendulum. amplitude of oscillation = ………………….. mm [1] (e) The pendulum achieves velocity v in the horizontal direction during its oscillation. Using the axis of Fig. 2.2, sketch the variation as the pendulum oscillates, of v with x, as air resistance is no longer negligible, starting from initial release position until the pendulum comes to a rest, after 2 cycles. Fig. 2.2 [2]

River Valley High School Page 8 of 24 H2 Physics 9749 2025 JC 2 Preliminary Examinations 3 Fig. 3.1 shows two coherent loudspeakers S1 and S2 placed 4.0 m apart in an open field. D is a detector placed in the same horizontal plane as the loudspeakers. D is placed 12.0 m away from S2. When the loudspeakers are switched on, sound of frequency 1780 Hz is emitted from the two loudspeakers in antiphase. The lines S1S2 and S2D are perpendicular to each other. Fig. 3.1 (a) Given that the speed of sound in air is 330 m s−1, calculate the wavelength  of the sound emitted from S1 and S2.  = ………………….. m [1] (b) Calculate the path difference, in terms of , between the sound waves reaching D from S1 and S2. You may assume that the two loudspeakers and the detector are point objects. path difference = …………………..  [2] D S1 S2 12.0 m 4.0 m

River Valley High School Page 9 of 24 H2 Physics 9749 2025 JC 2 Preliminary Examinations (c) By considering the phase difference between the sound waves reaching D from S1 and S2, explain whether D would detect a minimum or maximum intensity. ………………..…………………………………………………………………………… ………………..…………………………………………………………………………… ………………..…………………………………………………………………………… ….…………………………………………………………………………...……… [2] (d) As the frequency of the sound from S 1 and S 2 is gradually increased from 1780 Hz to a value f1, the resultant intensity at D goes through a series of maxima and minima. It eventually detects 2 complete cycles of change in sound intensity. Calculate the frequency f1 at which the second complet