(SAJC) 2024 H2 Phy Prelim P3 qn for sharing

1 SAJC Prelims 2024 9749/03 [Turn Over Class Index Number Name 23S ST. ANDREW’S JUNIOR COLLEGE JC 2 2024 Preliminary Examination _________________________________________________________________________ PHYSICS, Higher 2 9749/03 Paper 3 Longer Structured Questions 11th September 2024 2 hours Candidates answer on the Question Paper. No Additional Materials are required. _________________________________________________________________________ READ THESE INSTRUCTIONS FIRST Write your name, index number and Civics 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 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. 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. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Section A 1 / 15 2 / 6 3 / 6 4 / 8 5 / 7 6 / 10 7 / 8 Section B 8 / 20 9 / 20 Total / 80

2 SAJC Prelims 2024 9749/03 [Turn Over This document consists of 26 printed pages including this page. Data speed of light in free space c = 3.00 x 108 m s-1 permeability of free space μo = 4 π x 10-7 H m-1 permittivity of free space εo = 8.85 x 10-12 F m-1 = (1/(36π)) x 10-9 F m-1 elementary charge e = 1.60 x 10-19 C the Planck constant h = 6.63 x 10-34 J s unified atomic mass constant u = 1.66 x 10-27 kg rest mass of electron me = 9.11 x 10-31 kg rest mass of proton mp = 1.67 x 10-27 kg molar gas constant R = 8.31 J K-1 mol-1 the Avogadro constant NA = 6.02 x 1023 mol-1 the Boltzmann constant k = 1.38 x 10-23 J K-1 gravitational constant G = 6.67 x 10-11 N m2 kg-2 acceleration of free fall g = 9.81 m s-2 Formulae uniformly accelerated motion s = u t + ½ a t2 v2 = u2 + 2 a s work done on/by a gas W = p ΔV hydrostatic pressure p = ρ g h gravitational potential φ = temperature T / K = T / oC + 273.15 pressure of an ideal gas p = 1 3 𝑁𝑚 𝑉 〈𝑐2〉 mean translational kinetic energy of an ideal gas molecule E = kT displacement of particle in s.h.m. x = xo sin ω t velocity of particle in s.h.m. v = v0 cos ω t v = ± ω electric current I = Anvq resistors in series R = R1 + R2 + ... resistors in parallel 1 / R = 1 / R1 + 1 / R2 + ... electric potential V = alternating current/voltage x = xo sin ω t magnetic flux density due to a long straight wire B = 𝜇0𝐼 2𝜋𝑑 magnetic flux density due to a flat circular coil B = 𝜇0𝑁𝐼 2𝑟 magnetic flux density due to a long solenoid B = 𝜇0𝑛𝐼 radioactive decay x = xo exp (-λ t)

3 SAJC Prelims 2024 9749/03 [Turn Over decay constant λ = Answer all the questions in the space provided. 1 (a) The Earth spins on its axis with a period of one day. (i) Show that the angular velocity of a point on the Earth’s surface is 7.27 x 10-5 rad s-1. [1] (ii) Calculate the centripetal acceleration of a point on the Earth’s equator. The radius of the Earth’s equator is 6.38 x 106 m. centripetal acceleration = ………………… m s-2 [2] (b) The acceleration of free fall g at the equator is not equal to the acceleration of free fall at the poles. Explain (i) why they are different, ……………………………………………………………………………………….… ……………………………………………………………………………………….… …………………………………………………………………………………………. ………………………………………………………………………………………. [2] (ii) why the difference is small. ..……………………………………………………………………………………….. ……………………………………………………………………………………….… ………………………………………………………………………………… …….…

4 SAJC Prelims 2024 9749/03 [Turn Over ……………………………………………………………………………………… [2] (c) (i) State Newton’s law of gravitation. …..…………………………………………………………………………………… …………………………………………………………………………………….[1] (ii) The mass M of the Earth may be considered to be concentrated at its centre. The radius of the Earth is R. Derive, in terms of M and R, the equation relating the Earth’s gravitational field strength g to the gravitational constant G. Explain your working. [2]

5 SAJC Prelims 2024 9749/03 [Turn Over (d) (i) Calculate how far a satellite needs to be from the centre of the Earth for its angular velocity to be equal to the angular velocity of the Earth. distance =……………………….m [3] (ii) State two circumstances under which a satellite at this distance will be a geostationary satellite. 1. ……………………………………………………………………………………… ...………………………………………………………………………………………… 2. …..………………………………………………………………………….……… .……………………………………………………………………………………... [2]

6 SAJC Prelims 2024 9749/03 [Turn Over 2 The first law of thermodynamics, when applied to a system, can be expressed as: ΔU = q + w where ΔU is the increase in internal energy of the system, q is the heat supplied to the system and w is the work done on the system. State and explain, in terms of the first law of thermodynamics, the change, if any, in the internal energy (a) of the water in an ice cube when ice melts, at atmospheric pressure, to form a liquid without any change of temperature, ………..………………………………………………………………………………………… ………..………………………………………………………………………………………… ……….…………………………………………………………………………………………. ……….……………………………………………………………………………………….[3] (b) of the gas in a tyre when the tyre bursts so that the gas suddenly increases in volume. Assume that the gas is ideal. ……….………………………………………………………………………………………… ……….………………………………………………………………………………………… ……….…………………………………………………………………………………………. ……….……………………………………………………………………………………….[3]

7 SAJC Prelims 2024 9749/03 [Turn Over 3 (a) Explain qualitatively how molecular movement causes the pressure exerted by a gas. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. …………………………………………………………………………………………………... ……………………………………………………………………………………………….. [3] (b) A fixed mass of neon gas has a pressure of 1.02 × 10 5 Pa and density of 0.900 kg m–3. Neon may be assumed to be an ideal gas. Calculate the root-mean-square speed of neon atoms. speed = ................................................ m s–1 [2] (c) The density of the neon gas in (b) is now varied, keeping its pressure constant. On Fig. 3.1, sketch the variation with volume V of the internal energy U of the gas.

8 SAJC Prelims 2024 9749/03 [Turn Over [1] Fig. 3.1 4 A tube, closed at one end, has a uniform area of cross-section. The tube contains some sand so that the tube floats upright in a liquid, as shown in Fig. 4.1 Fig. 4.1 When the tube is at rest, the depth d of immersion of the base of the tube is 16 cm. The tube is displaced vertically and then released. The variation with time t of the depth d of the base of the tube is shown in Fig. 4.2. Fig. 4.2

9 SAJC Prelims 2024 9749/03 [Turn Over (a) Use Fig. 4.2 to determine, for the oscillations of the tube, the amplitude. amplitude = ................................................. cm [1] (b) (i) Ca