2025 HCI C2 Prelim H2 Physics P2 QP

This document consists of 24 printed pages, including 2 blank pages. HWA CHONG INSTITUTION JC2 Preliminary Examination Higher 2 CANDIDATE NAME CT GROUP 24S CENTRE NUMBER INDEX NUMBER PHYSICS Paper 2 Structured Questions Candidates answer on the Question Paper. No Additional Materials are required. 9749/02 16 September 2025 2 hours READ THESE INSTRUCTIONS FIRST Write your Centre Number, Index Number, Name and CT Group in the spaces at the top of this page. Write in dark blue or black pen on both sides of the paper. You may use a soft 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. The number of marks is given in brackets [ ] at the end of each question or part question. You are reminded of the need for good English and clear presentation in your answers. For Examiner’s Use Paper 2 1 7 2 8 3 12 4 7 5 9 6 8 7 8 8 21 Deductions Total 80

2 © Hwa Chong Institution 9749 / 02 / Preliminary Examination 2025 Data Formulae speed of light in free space, c = 3.00  10 8 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  10 23 mol -1 the Boltzmann constant, k = 1.38  10 -23 J K -1 gravitational constant, G = 6.67  10 -11 N m 2 kg -2 acceleration of free fall, g = 9.81 m s -2 uniformly accelerated motion work done on / by a gas hydrostatic pressure gravitational potential temperature pressure of an ideal gas mean kinetic energy of a molecule of an ideal gas displacement of particle in s.h.m. velocity of particle in s.h.m. electric current resistors in series resistors in parallel electric potential alternating current / voltage magnetic flux density due to a long straight wire magnetic flux density due to a flat circular coil magnetic flux density due to a long solenoid radioactive decay decay constant s = ut + 2 1 at2 v 2 = u 2 + 2as W = p V p = gh r Gm−= T/K = T/ C + 273.15 P = 21 3 Nm cV  kTE 2 3= x = xo sin t v = vo cos t = )( 22 xxo − I = Anvq R = R1 + R2 + . . . 1/R = 1/R1 + 1/R2 + . . . r QV o4= x = xo sin  t 2 oμB d=  I 2 oμNB r= I B = onI x = xo exp ( -t ) 1 2 ln2 t =

3 © Hwa Chong Institution 9749 / 02 / Preliminary Examination 2025 BLANK PAGE

4 © Hwa Chong Institution 9749 / 02 / Preliminary Examination 2025 1 (a) Fig 1.1 shows a fluid of density ρ in a rectangular container. The height of the liquid is h. Fig 1.1 Show that the pressure P at the bottom of the container due to the fluid is given by P gh= [2] (b) (i) An object of mass m and density d is surrounded by air of density ρ. Show that the resultant force F acting downward on the object is given by 1F mg d =−  [2] h

5 © Hwa Chong Institution 9749 / 02 / Preliminary Examination 2025 (ii) A chemist uses an accurate balance to weigh a sample as shown in Fig. 1.2. Fig. 1.2 The mass of the standard mass is 0.17851 kg. The density of the sample is 940.0 kg m -3, the density of the standard mass is 8493 kg m-3, and the density of air is 1.29 kg m-3. Using your answer in (b)(i), calculate the mass of the sample. Leave your answer to 5 decimal places. mass = …………………….. kg [3] [Total: 7 marks] standard mass sample

6 © Hwa Chong Institution 9749 / 02 / Preliminary Examination 2025 2 An object of mass m of 0.42 kg is attached to a spring S and the system is made to oscillate with simple harmonic motion on a horizontal, frictionless surface, as shown in Fig 2.1. The mass passes through the equilibrium position at P 200 times per minute. Fig 2.1 The kinetic energy of the mass as it passes through the equilibrium position is 500 mJ. (a) (i) Determine the period of the oscillation. period = …………………….. s [1] (ii) Show that the amplitude of the oscillation is approximately 15 cm. [3] m P S

7 © Hwa Chong Institution 9749 / 02 / Preliminary Examination 2025 (iii) Sketch in Fig 2.2 the variation with time of the velocity of the mass for 2 cycles. Label the axes with appropriate values. Fig 2.2 [2] (b) Deduce the change, if any, to the frequency of the oscillation if the following modifications are made separately to the experiment: (i) the experiment is done on Mars instead of the Earth, ……………………………………………………………………………………………………….. …………………………………………………………………………………………………...... [1] (ii) another spring identical to S is connected in parallel, as shown in Fig 2.3. Fig 2.3 ……………………………………………………………………………………………………….. …………………………………………………………………………………………………...... [1] [Total: 8 marks] velocity / m s -1 time / s m P

8 © Hwa Chong Institution 9749 / 02 / Preliminary Examination 2025 3 (a) Define gravitational potential at a point. ………………………………………………………………………………………………………………… …………………………………………………………………………………………………………….. [2] (b) The neutral point is the point where the gravitational field strength due to Earth is equal in magnitude and opposite in direction to the gravitational field strength due to the Moon. The gravitational potential s at the Earth ’s and Moon’s surfaces are –62.3 × 106 J kg -1 and –3.90 × 106 J kg-1 respectively. A 10.0 kg mass projected from the Earth’s surface needs 6.10 x 10 8 J of kinetic energy to just reach the neutral point from the Earth. The effects of air resistance may be neglected. (i) Determine the gravitational potential at the neutral point. gravitational potential = ……………… J kg-1 [2] (ii) Determine the minimum kinetic energy needed to send a 1.4 kg rock from the surface of the Moon to the surface of the Earth. minimum kinetic energy =…………………. J [3]

9 © Hwa Chong Institution 9749 / 02 / Preliminary Examination 2025 (c) Two stars of mass M and 2M, a distance of 3R apart, rotate in circles about their common centre of mass O. Fig 3.1 The period of this binary star system is 3.42 x 105 s. The value of M is  303.14 10 kg. (i) Explain why the two stars experience the same magnitude of centripetal force. …………………………………………………………………………………………………………. …………………………………………………………………………………………………………. ………………………………………………………………………………………………………. [2] (ii) Determine the distance R. R = ………………………… m [3] [Total: 12 marks] M R R O 2M

10 © Hwa Chong Institution 9749 / 02 / Preliminary Examination 2025 4 (a) Waves from a point source pass through an area that is 1.6 cm wide, as shown in Fig. 4.1. Fig. 4.1 Within this area, the intensity of the waves is I0 and their amplitude is A0. The waves reach a second ar