Prelim (H2) P3 2021_QP and Solutions

1 Class Index Number Name 20S ST. ANDREW’S JUNIOR COLLEGE JC 2 2021 Preliminary Examination PHYSICS, Higher 2 9749/03 Paper 3 Longer Structured Questions 16th September 2021 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 on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use a 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. 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. This document consists of 21 printed pages including this page. SAJC 2021 Preliminary Examination / 9749 [Turn Over For Examiner’s Use Section A 1 / 12 2 / 9 3 / 10 4 / 11 5 / 18 Section B 6 / 20 Total / 80

2 Data speed of light in free space c = 3.00 x 108 m s-1 permeability of free space mo = 4 p x 10-7 H m-1 permittivity of free space eo = 8.85 x 10-12 F m-1 = (1/(36p)) 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 DV hydrostatic pressure p = g h gravitational potential f = −Gm r 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 = 3 2 kT displacement of particle in s.h.m. x = xo sin t velocity of particle in s.h.m. v = v0 cos w t v = ± w √ x0 2− 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 πε0 r alternating current/voltage x = xo sin  t magnetic flux density due to a long straight wire B = μ0 I 2πd magnetic flux density due to a flat circular coil B = μ0 NI 2r magnetic flux density due to a long solenoid B = μ0 n I radioactive decay x = xo exp (-l t) SAJC 2021 Preliminary Examination / 9749 [Turn Over

3 decay constant  = ln 2 t1/2 SAJC 2021 Preliminary Examination / 9749 [Turn Over

4 Section A Answer all questions in the spaces provided 1 (a) Phobos is one of the two moons orbiting Mars. Fig. 1.1 shows Phobos and Mars. Fig. 1.1 The orbit of Phobos may be assumed t