ASRJC 2025 H2 Physics Prelim P2

1 9749/02/ASRJC/2025Prelim [Turn over Name: _____________________________ ( ) Class: 25 / ______ 2025 JC2 Preliminary Examination PHYSICS Higher 2 9749/02 Paper 2 Structured Questions Friday 22 August 2025 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class index number and class 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 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. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 23 printed pages and 1 blank page. For Examiner’s Use Paper 2 (80 marks) 1 2 3 4 5 6 7 Deductions Total ANDERSON SERANGOON JUNIOR COLLEGE

2 9749/02/ASRJC/2025Prelim 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

3 9749/02/ASRJC/2025Prelim [Turn over Formulae uniformly accelerated motion s 2 2 1 atut  2v asu 22  work done on/by a gas W Vp hydrostatic pressure p gh gravitational potential  r Gm temperature T/K  T/C + 273.15 pressure of an ideal gas p   2 3 1 cV Nm 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  d o   2 I magnetic flux density due to a flat circular coil B  r No 2 I magnetic flux density due to a long solenoid B  Ino radioactive decay x  x0 exp(–t) decay constant   2 1 2ln t

4 9749/02/ASRJC/2025Prelim Answer all the questions in the spaces provided. 1 (a) The acceleration of free fall g may be determined from an oscillating pendulum using the equation l 2 2 4g T where l is the length of the pendulum and T is the period of oscillation. In an experiment, the measured values for an oscillating pendulum are l = 1.50 m ± 2% and T = 2.48 s ± 3%. (i) Calculate the acceleration of free fall g. g = ..................................... m s2 [1] (ii) Determine the actual uncertainty of the calculated value of g. actual uncertainty = …………………………. m s2 [2]

5 9749/02/ASRJC/2025Prelim [Turn Over (b) A trolley on a track is attached by springs to fixed blocks X and Y, as shown in Fig. 1.1. The track contains many small holes through which air is blown vertically upwards. This results in the trolley resting on a cushion of air rather than being in direct contact with the track. Fig. 1.1 The trolley is pulled to one side of its equilibrium position and then released so that it oscillates initially with simple harmonic motion. After a short time, the air blower is switched off. The variation with time t of the distance L of the trolley from block X is shown in Fig. 1.2. Fig. 1.2

6 9749/02/ASRJC/2025Prelim (i) Use Fig. 1.2 to determine the maximum speed v0, of the oscillating trolley. v0 = ..................................... cm s1 [2] (ii) Apart from the quantities determined in (b)(i), describe what may be deduced from Fig. 1.2 about the motion of the trolley between time t = 0 and time t = 24 s. No calculations are required. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………….………….... [2] (iii) On Fig. 1.3, sketch the variation with L of the velocity v of the trolley for its first complete oscillation. Fig. 1.3 [2] [Total: 9]

7 9749/02/ASRJC/2025Prelim [Turn Over 2 (a) A block is pulled by a force X along a rough surface inclined at 30  to the horizontal, as shown in Fig. 2.1. The weight of the block is 0.80 N. Fig. 2.1 (not to scale) Assume that the total resistive force opposing the motion of the block is 0.40 N at all speeds of the block. The variation with time t of the magnitude of the force X is shown in Fig. 2.2. Fig. 2.2 (i) Show that the change in momentum of the block from time t = 0 to time t = 3.0 s is 1.8 kg m s–1. [2] (ii) Describe and explain the motion of the block between time t = 3.0 s and time t = 6.0 s. ………………………………………………………………………………….................... ………………………………………………………………………………….................... ……………………………………………………………………………….………….... [2] 30

8 9749/02/ASRJC/2025Prelim (iii) The block is at rest at time t = 0. On Fig. 2.3, sketch a graph to show the variation of the momentum of the block with time t from t = 0 to t = 6.0 s. Numerical values of momentum are not required. Fig. 2.3 [2] (b) A nucleus P and a nucleus Q are moving towards each other at the same speed v as shown in Fig. 2.4. The mass of nucleus Q is smaller than that of nucleus P. The interaction between the nuclei is elastic. Fig. 2.4 The variation with time t of the velocity of each nucleus is shown in Fig. 2.5. Fig. 2.5 (not to scale) P Q v v

9 9749/02/ASRJC/2025Prelim [Turn Over (i) Explain why it is not possible for the nuclei to stop at the same instant. ………………………………………………………………………………….................... ………………………………………………………………………………….................... ……………………………………………………………………………….………….... [2] (ii) On Fig. 2.5, label the curve for nucleus Q. Explain your reasoning. ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ……………………………………………………………………………….…………….[3] [Total: 11]

10 9749/02/ASRJC/2025Prelim 3 (a) State what is meant by a line of force in (i) a gravitational field, ……………………………………………………………………………….…………........ ……………………………………………………………………………….………….... [1] (ii) an electric field. ……………………………………………………………………………….…………........ ……………………………………………………………………………….………….... [1] (b) State one similarity and one difference between the electric field lines and the gravitational field lines around an isolated positively charged metal sphere. similarity ……………………………………………………………………................................ ………………………………………………………………………………….........................