ACJC 2022 Prelim P3

This paper consists of 28 printed pages Anglo-Chinese Junior College Physics Preliminary Examination Higher 2 CANDIDATE NAME CLASS CENTRE NUMBER S 3 0 0 4 INDEX NUMBER PHYSICS Paper 3 Longer Structured Questions Candidates answer on the Question Paper. No Additional Materials are required. 9749/03 30 August 2022 2 hours READ THESE INSTRUCTIONS FIRST Write your name, class and index number 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, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Section A Answer all questions. Section B Answer one question only. You are advised to spend one and a half hours on Section A and half an hour on Section B. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiners’ use only Section A 1 / 12 2 / 10 3 / 12 4 / 12 5 / 14 Total / 60 Section B 6 / 20 7 / 20 Grand Total / 80

2 Anglo-Chinese Junior College 2022 J2 H2 9749 Paper 3 Preliminary Examination DATA AND FORMULAE 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 [Turn over Anglo-Chinese Junior College 2022 J2 H2 9749 Paper 3 Preliminary Examination Formulae uniformly accelerated motion, s = ut + 2 1 at 2 v 2 = u 2 + 2as work done on/by a gas, W = p V hydrostatic pressure, p =  g h gravitational potential,  = − Gm r temperature T/K = T/oC + 273.15 pressure of an ideal gas p = 21 3 Nm c V  mean translational kinetic energy of an ideal gas molecule, E = 3 2 kT displacement of particle in s.h.m., x = xo sin t velocity of particle in s.h.m., v = vo cos t =   22 oxx − electric current I = Anvq resistors in series, R = R1 + R2 +  resistors in parallel, 1/R = 1/R1 + 1/R2 +  electric potential, V = 4 o Q r alternating current/voltage, x = xo sin t magnetic flux density due to a long straight wire B = 2 o d   magnetic flux density due to a flat circular coil B = 2 oN r  magnetic flux density due to a long solenoid B = on radioactive decay, x = xo exp(−t) decay constant,  = 12 ln2 t

4 Anglo-Chinese Junior College 2022 J2 H2 9749 Paper 3 Preliminary Examination For Examiner’s Use Section A Answer all the questions in this Section in the spaces provided. 1 A student is exploring Physics principles with wooden blocks and some Physics activities. (a) Fig. 1.1 shows the first experiment with block A attached to a frictionless pulley using an inelastic massless string. Block A accelerates up a frictionless inclined plane of angle 50°. Block B of mass 8.3 kg is attached to the string on the opposite end of the pulley. Fig. 1.1 (i) On Fig. 1.2, label the forces acting on block A. Fig. 1.2 [1]

5 [Turn over Anglo-Chinese Junior College 2022 J2 H2 9749 Paper 3 Preliminary Examination For Examiner’s Use (ii) The tension of the string is 54 N. Show that the mass of block A is 5.0 kg. [3] (b) Fig. 1.3 shows another experiment with block A from (a). Block A moves along a frictionless horizontal plane towards a stationary block C of mass 10 kg at a constant speed. Block A collides with block C at t = 0 s. Fig. 1.3 The variation with time t of the momentum p of block A is shown in Fig. 1.4. Fig. 1.4

6 Anglo-Chinese Junior College 2022 J2 H2 9749 Paper 3 Preliminary Examination For Examiner’s Use (i) Determine the force acting on block C during the collision. force = ……………………… N [2] (ii) Calculate the velocity of block A after the collision. velocity = ……………………… m s–1 [2] (iii) Deduce whether the collision between the two blocks is elastic or inelastic. Show your working. ………………………………………………………………………………………… …………………………………………………………………………………..… [4] [Total: 12]

7 [Turn over Anglo-Chinese Junior College 2022 J2 H2 9749 Paper 3 Preliminary Examination For Examiner’s Use 2 (a) Define electric potential at a point. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. ……………………………………………………………………………………….... [2] (b) A thin hollow conducting sphere A of radius 0.050 m has an electric potential V of 400 V and an electric field strength E of 8000 N C –1 at its surface as shown in Fig. 2.1. Fig. 2.1 distance from centre of A / m V / V E / N C–1 0.050 400 8000 0.200 Complete Fig. 2.1 for the electric potential V and electric field strength E at 0.200 m from the centre of sphere A. [2] (c) Sphere A is placed inside a second thin hollow conducting sphere B of radius 0.200 m carrying a charge of the same magnitude but opposite sign as the charge on A. The spheres have a common centre as shown in Fig. 2.2(a) and Fig. 2.3(a). Without further calculations, use values in (b) to sketch graphs of the variation with distance r from the common centre for (c)(i) and (c)(ii) below. Take the positive direction of electric field strength E to be in the positive horizontal axis. (i) When only sphere A is present. 1. electric potential on Fig. 2.2(b). Label VA. [2] 2. electric field strength on Fig. 2.2(c). Label EA. [2] (ii) When both spheres A and B are present. 1. electric potential on Fig. 2.3(b). Label VR. [1] 2. electric field strength on Fig. 2.3(c). Label ER. [1] [Total: 10]

8 Anglo-Chinese Junior College 2022 J2 H2 9749 Paper 3 Preliminary Examination For Examiner’s Use Fig. 2.2(a) Fig. 2.2(c) A 0 0 r / m V / V − 0.20 − 0.10 0.10 0.20 400 Fig. 2.2(b) 0 0 r / m E / N C-1 0.10 0.20 − 0.20 − 0.10 8000

9 [Turn over Anglo-Chinese Junior College 2022 J2 H