EJC 2025 J2 H2 PRELIM P2

©EJC 2025 9749/J2H2PRELIM2025 [Turn over EUNOIA JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS 2025 General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CIVICS GROUP 2 4 - REGISTRATION NUMBER PHYSICS Structured Questions 9749/02 September 2025 2 hours READ THESE INSTRUCTIONS FIRST Write your name, civics group and registration number on all the work you hand in. The use of an approved scientific calculator is expected where appropriate. Answer all questions. 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 paper clips, highlighters, glue or correction fluid. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 24 printed pages. For Examiner’s Use Q1 6 Q2 11 Q3 5 Q4 7 Q5 9 Q6 8 Q7 6 Q8 8 Q9 20 s.f. P2 Total 80

2 ©EJC 2025 9749/J2H2PRELIM2025 Data speed of light in free space, ( )( ) 81 71 0 12 1 0 91 19 34 27 31 e 27 p 11 23 1 A 23 1 10 m s 10 H m 10 F m 10 F m 10 C 6 63 10 J s 1 3 00 4 8 85 1 36 1 60 9 11 1 67 66 10 kg 10 kg 10 kg J K mol 6 02 10 8 31 1 38 mol 10 J K c. . / e h. u. m m . . . R. N k . . G    − −− −− −− − − − − − −− − −−      = = = =   = = = = = = = =  11 2 2 2 10 N m kg m 67 81 s 6 9 . g. −− − = =  permeability of free space, permittivity of free space, elementary charge, the Planck constant, unified atomic mass constant, rest mass of electron, rest mass of proton, molar gas constant, the Avogadro constant, the Boltzmann constant, gravitational constant, acceleration of free fall,

3 ©EJC 2025 9749/J2H2PRELIM2025 [Turn over Formulae uniformly accelerated motion, ( ) ( ) 2 22 2 0 0 22 0 12 12 0 0 0 0 0 0 1 2 1 2 2 / K / C 273 15 1 3 3 2 sin cos 1 1 1 4 sin 2 2 exp ln2 at u as V p gh Gm r T T . Nmpc V kT x x t v v t xx R / R / R / R QV r x x t B d NB r s ut v Wp t E Bn t Anvq RR xx              =+  = =− =  + = = = = − ++ = + + = = = = = − = =+ = = = = = I I I I work done on/by a gas, hydrostatic pressure, gravitational potential, temperature, pressure of an ideal gas, mean translational kinetic energy of an ideal gas molecule 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

4 ©EJC 2025 9749/J2H2PRELIM2025 1 A student proposes that the speed v of a sound wave through a gas of pressure P and density  is given by the equation 3 kPv = where k is a constant with no unit. An experiment is performed to determine the value of k. The data from the experiment are shown in Table 1.1. Table 1.1 quantity value v 213.3 10 m s − percentage uncertainty = 8% P 49.9 10 Pa fractional uncertainty = 0.07  31.29 kg m− absolute uncertainty = 30.09 kg m− (a) Use data from Table 1.1 to calculate k. k = .......................................................... [1] (b) Use your answer in (a) and data from Table 1.1 to determine the value of k, with its absolute uncertainty, to an appropriate number of significant figures. k = ....................................... ± ....................................... [3]

5 ©EJC 2025 9749/J2H2PRELIM2025 [Turn over (c) It is proposed in that in the presence of wind, the actual speed u of the sound wave of frequency f is u v fA=+ Derive the unit for A. unit = ………………………… [2] [Total: 6]

6 ©EJC 2025 9749/J2H2PRELIM2025 2 (a) An Olympic diver stands on a platform above a pool of water, as shown in Fig. 2.1. When the diver is on the platform his centre of gravity is a vertical height of 9.0 m above the surface of the water. The diver jumps from the platform with a velocity of 5.9 m s–1 at an angle of 60o to the horizontal. Air resistance is negligible. When the diver hits the surface of the water, his centre of gravity is a vertical height of 1.2 m above the surface of the water. (i) Calculate the time it takes him to hit the surface of the water. time = ................................................ s [2]

7 ©EJC 2025 9749/J2H2PRELIM2025 [Turn over (ii) Calculate the angle from the water surface when he hits the surface of the water. angle = …………………………… o [3] (b) The diver in (a) enters the water. (i) Explain the why the resultant force acting on the diver in decreases in the water as he moves downwards. ………………………………………………………………………………………………... ………………………………………………………………………………………………... ………………………………………………………………………………………………... ………………………………………………………………………………………………... …………………….……………………………………………………………………… [2] (ii) The diver has a volume of 7.5 × 10 –2 m3. The density of the water is 1.0 × 103 kg m–3. Show that the upthrust acting on the diver when he is entirely underwater is 740 N. [1]

8 ©EJC 2025 9749/J2H2PRELIM2025 (iii) At a particular instant when the diver is entirely underwater his horizontal velocity is zero. The viscous drag force acting on him at this instant is 950 N vertically upwards. The diver has a mass of 78 kg. Determine the magnitude and direction of the acceleration of the diver. acceleration = ...................................................... m s–2 direction ............................................................... [3] [Total: 11]

9 ©EJC 2025 9749/J2H2PRELIM2025 [Turn over 3 (a) State the principle of moments. ………………………………………………………………………………………..………........... …………………………………………………………………………………………..…………… ……………………………………………………………………………………..…………..… [2] (b) A uniform rod of weight 1000 N rests at angle of 30 to the ground. It is in equilibrium when supported by tension T which acts 47o from the horizontal, as shown in Fig. 3.1. Fig. 3.1 Calculate the tension T. T = ...................................................... N [3] [Total: 5] 1000 N 30 47o T ground rod

10 ©EJC 2025 9749/J2H2PRELIM2025 4 In Fig. 4.1 below, a trolley of mass 0.50 kg moves with a velocity 2.0 m s−1 towards a stationary pendulum bob of mass 0.20 kg, which is hung on a light string at a distance of 1.5 m from the ceiling. The trolley collides elastically with the pendulum bob and the pendulum bob then swings upwards. (a) Calculate the speed of the pendulum bob immediately after the collision. speed = .......................................................... m s−1 [3] 2.0 m s−1 Fig. 4.1 1.5 m pendulum bob ceiling trolley