Prelim H2P2

1 Name: _____________________________ ( ) Class: 21 / ______ 2021 JC2 Preliminary Examination PHYSICS Higher 2 9749/02 Paper 2 Structured Questions Wednesday 1 September 2021 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. The use of an approved scientific calculator is expected, where appropriate. Answer all questions. 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. 9749/02/ASRJC/2021PRELIM [Turn over ANDERSON SERANGOON JUNIOR COLLEGE For Examiner’s Use Paper 2 (80 marks) 1 2 3 4 5 6 7 Deduction Total This document consists of 21 printed pages and 3 blank pages.

2 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 9749/02/ASRC/2021PRELIM

3 Formulae uniformly accelerated motion s = ut + 1 2 at 2 v2 = u2 + 2 as work done on/by a gas W= pΔV hydrostatic pressure p= ρ gh gravitational potential φ= −Gm r temperature T/K  T/C + 273.15 pressure of an ideal gas p  1 3 Nm V ⟨ c2⟩ mean translational kinetic energy of an ideal gas molecule E= 3 2 kT displacement of particle in s.h.m. x  x0 sin  t velocity of particle in s.h.m. v  v0 cos  t = ±ω√ xo2−x2 electric current I  Anvq resistors in series R = R1 + R2 + … resistors in parallel 1/R = 1/R1 + 1/R2 + … electric potential V = Q 4 πεo r alternating current/voltage x = x0 sin  t magnetic flux density due to a long straight wire B  μo I 2 πd magnetic flux density due to a flat circular coil B  μo∋ ¿ 2 r ¿ magnetic flux density due to a long solenoid B  μo∋¿ ¿ radioactive decay x = x0 exp(–t) decay constant   ln 2 t 1 2 9749/02/ASRJC/2021PRELIM [Turn over

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5 Answer all the questions in the spaces provided. 1 (a) State one similarity and one difference between the electric field lines and the gravitational field lines around an isolated positively charged metal sphere. similarity: ............................................................................................................................. ............................................................................................................................................. difference: ........................................................................................................................... ........................................................................................................................................ [2] (b) (i) Define gravitational potential at a point. ………………………………………………………………………………….................... ………………………………………………………………………………….................... ……………………………………………………………………………….………….... [2] (ii) Use your answer in (b)(i) to explain why the gravitational potential near an isolated mass is always negative. ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ………………………………………………………………………………….................... ……………………………………………………………………………….………….... [3] (c) A spherical planet has mass 6.00 × 10 24 kg and radius 6.40 × 10 6 m. The planet may be assumed to be isolated in space with its mass concentrated at its centre. A satellite of mass 340 kg is to be raised from the planet to a height of 9.00 × 10 5 m above the surface of the planet. (i) Calculate the increase in potential energy of the satellite. 9749/02/ASRJC/2021PRELIM [Turn Over

6 increase in potential energy = ………………….. J [2] (ii) On the axes of Fig. 1.1, sketch a graph to show the variation of the gravitational force on the satellite with distance between the planet and the satellite, as the satellite is raised from the planet to its final position. [2] (iii) State what the area under the graph in (c)(ii) represents. ………………………………………………………………………………….................... ………………………………………………………………………………….................... ……………………………………………………………………………….………….... [1] [Total: 12] 9749/02/ASRC/2021PRELIM force distance planet’s surface final position of satellite Fig. 1.1 0

7 2 (a) The kinetic theory of gases is based on a number of assumptions about the molecules of a gas. State the assumption that is related to the volume of the molecules of the gas. …………………………………………………………………………………………….………… …………………………………………………………………………………………….......... [1] (b) An ideal gas occupies a volume of 2.40 × 10–2 m3 at a pressure of 4.60 × 105 Pa and a temperature of 23 °C. Each molecule has a diameter of approximately 3 × 10–10 m. Estimate the total volume of the gas molecules. volume = ……………………………m 3 [3] (c) By reference to your answer in (b), suggest why the assumption in (a) is justified. …………………………………………………………………………………………….………… …………………………………………………………………………………………….......... [1] 9749/02/ASRJC/2021PRELIM [Turn Over

8 (d) The ideal gas undergoes the cycle of changes PQRP as shown in Fig. 2.1. Some energy changes during one cycle PQRP are shown in Fig. 2.2. change P → Q change Q → R change R → P thermal energy transferred to gas / J work done on gas / J increase in internal energy of gas / J +97.0 ........................ ........................ 0 –42.5 ........................ ........................ ........................ ........................ On Fig. 2.2, complete the energy changes for the gas. [5] [Total: 10] 9749/02/ASRC/2021PRELIM Fig. 2.1 Fig. 2.2

9 3 A hollow tube, sealed at one end, has a cross-sectional area A of 24 cm2. The tube contains sand so that the total mass M of the tube and sand is 0.23 kg. The tube floats upright in a liquid of density , as illustrated in Fig. 3.1. The depth of the bottom of the tube below the liquid surface is h. The tube is displaced vertically and then released. The variation with time t of the depth h is shown in Fig. 3.2. 9749/02/ASRJC/2021PRELIM [Turn Over Fig. 3.1 Fig. 3.2

10 (a) Determine the acceleration of the tube when h is a maximum. acceleration = ……………………………. m s–2 [3] (b) Describe the restoring force that gives rise to the oscillations of the tube. …………………………………………………………………………………………….………… …………………………………………………………………………………………….………… …………………………………………………………………………………………….………… …………………………………………………………………………………………….......... [2] (c) The oscillations illustrated in Fig. 3.2 are undamped. In practice, the liquid does cause light damping. On Fig. 3.2, draw a line to show light damping of the oscillations for time t = 0 to time t = 1.4 s. [3] [Total: 8] 9749/02/ASRC/2021PRELIM