DHS 2023 H2 Phy P3

© DHS 2023 9749/03 [Turn over Name: Centre/Index Number: Class: DUNMAN HIGH SCHOOL Preliminary Examination Year 6 H2 PHYSICS Paper 3 Longer Structured Questions Candidates answer on the Question Paper 9749/03 21 September 2023 2 hours READ THESE INSTRUCTIONS FIRST Write your centre number, index number, name and class at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions. Section B Answer any one question. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Section A 1 8 2 10 3 9 4 6 5 9 6 10 7 8 Section B 8 / 9 20 Total 80 This document consists of 25 printed pages and 1 blank page.

2 © DHS 2023 9749/03 [Turn over Data speed of light in free space, c = 3.00 × 108 m s−1 permeability of free space, µo = 4π × 10−7 H m−1 permittivity of free space, εo = 8.85 × 10−12 F m−1 (1/(36π)) × 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 © DHS 2023 9749/03 [Turn over Formulae uniformly accelerated motion, s = ut + at2 v2 = u 2 + 2as work done on/by a gas, W = p∆V hydrostatic pressure, p = ρgh gravitational potential, φ = −Gm/r temperature, T/K = T/oC + 273.15 pressure of an ideal gas, p = mean translational kinetic energy of an ideal gas molecule, E = displacement of particle in s.h.m., x = x 0 sin ωt velocity of particle in s.h.m., v = v0 cos ωt = ±ω electric current, I = Anvq resistors in series, R = R1 + R2 + . . . resistors in parallel, 1/R = 1/R 1 + 1/R2 + . . . electric potential, V = alternating current / voltage, x = x0 sin ωt magnetic flux density due to a long straight wire, B = magnetic flux density due to a flat circular coil, B = magnetic flux density due to a long solenoid, B = radioactive decay, x = x 0 exp(−λt) decay constant, λ = 1 2 21 3 Nm cV <> kT2 3 2 2x xo − r Q oπε4 0 2 d Iµ π 0 2 N r Iµ 0nIµ 1 2 ln 2 t

4 © DHS 2023 9749/03 Section A Answer all the questions in this section in the spaces provided. 1 A tritium nucleus moves towards a deuterium nucleus as illustrated in Fig. 1.1. Fig. 1.1 The two nuclei initially have the same speed v and the interaction between the two nuclei is elastic. The tritium nucleus consists of two neutrons and a proton. The deuterium nucleus consists of a neutron and a proton. Assume that t he proton and the neutron have the same mass m. (a) State the principle of conservation of momentum. …………………………………………………………………………….……………………….. …………………………………………………………………………….……………………….. …………………………………………………………………………….……………………….. …………………………………………………………………………….……………………. [1] (b) Explain why it is not possible for the nuclei to stop at the same instant. …………………………………………………………………………….……………………….. …………………………………………………………………………….……………………….. …………………………………………………………………………….……………………….. …………………………………………………………………………….……………………….. ……………………………………………… …………………………….……………………. [2] v v tritium deuterium + +

5 © DHS 2023 9749/03 [Turn over (c) Determine the final velocities of each nucleus in terms of v. final velocity of deuterium = ........................................... final velocity of tritium = ........................................... [3] (d) Given that the interaction between the two nuclei took a total time of t seconds, express the magnitude of the average force that the deuterium nucleus exerts on the tritium nucleus in terms of m, v and t. magnitude of average force = ……................................ [2] [Total: 8]

6 © DHS 2023 9749/03 2 A 70.0 kg man standing on a platform makes a leap upwards with an initial speed of 2.00 m s−1 before falling towards a diving board that is located 1.50 m below the platform as shown in Fig. 2.1. Fig. 2.1 (a) Calculate the loss in gravitational potential energy as the man falls from the platform to a point just before he hits the diving board. loss in gravitational potential energy = ................................ J [1] (b) Calculate the initial kinetic energy possessed by the man at the start of his jump. initial kinetic energy = ................................ J [1] (c) The uniform rigid diving board has a length 4.80 m and weight 300 N. It is pivoted at a point 2.40 m away from its left end and is attached to an unstretched spring with a force constant of 10.0 kN m −1 on one end. When the man hits the diving board on the opposite end after jumping off the platform, the board rotates and causes the spring to stretch until the man comes to a momentary stop. At the instant that the man is momentarily at rest, the diving board makes an angle 𝜃𝜃 to the horizontal as shown in Fig. 2.2. diving board platform spring man 1.50 m 2.00 m s −1

7 © DHS 2023 9749/03 [Turn over Fig. 2.2 (i) Explain why the weight of the diving board does not produce any moments at the pivot. ……………………………………………………………………………........................ ……………………………………………………………………………........................ .……………………………………………………………………….………………... [1] (ii) Show that the angle of tilt 𝜃𝜃 is 13.4°. Explain your workings and state any assumptions made. [4] diving board spring 𝜃𝜃 man

8 © DHS 2023 9749/03 (iii) Assuming that the spring only exerts a force vertically on the diving board, calculate the force exerted by the spring on the diving board. force = ................................ N [1] (iv) Calculate the magnitude of the normal contact force exerted by the pivot on the diving board. magnitude of normal contact force = ................................ N [2] [Total: 10] 3 The Earth may be assumed to be an isolated uniform sphere with its mass of 6.0 × 10 24 kg concentrated at its centre. A satellite of mass 1200 kg is in a circular orbit about the Earth in the Earth’s gravitational field. The period of the orbit is 94 minutes. (a) Define gravitational field strength. …………………………………………………………………………….……………………….. …………………………………………………………………………….……………………. [1] (b) Calculate the radius of the orbit. radius = ...................................................... m [3]

9 © DHS 2023 9749/03 [Turn over (c) Rockets on the satellite are fired so that the satellite enters a different circular orbit that has a period of 150 minutes. (i) Show that the linear speed of the satellite in its new orbit is 6.6 × 103 m s−1. [3] (ii) Determine the change in the potential energy of the satellite. change in potential energy = ...................................................... J [2] [To