2021 H2 Phy Prelim Paper 3 Question Paper (forJCs)

©YIJC [Turn over YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CG INDEX NUMBER PHYSICS Paper 3 Longer Structured Questions Candidates answer on the Question Paper. No Additional Materials are required. 9749/03 15 September 2021 2 hours READ THESE INSTRUCTIONS FIRST This document consists of 25 printed pages and 3 blank pages. For Examiner’s Use Paper 3 Section A 1 /3 2 /7 3 /6 4 /4 5 /10 6 /10 7 /11 8 /9 Section B 9 /20 10 /20 Penalty /80 Write your name 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. Do not use staples, paper clips, highlighters, glue or correction fluid/tape. The use of an approved scientific calculator is expected, where appropriate. Section A Answer all questions. Section B Answer any one question. 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.

©YIJC [Turn over 2 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 Formulae uniformly accelerated motion, s = ut + 2 1 at2 v2 = u2 + 2as work done on/by a gas, W = p  V hydrostatic pressure, p =  g h gravitational potential,  = r Gm temperature, T/K = T/°C + 273.15 pressure of an ideal gas, p = 2CV Nm 3 1 mean translational kinetic energy of an ideal gas molecule, E = kT2 3 displacement of particle in s.h.m. x = xo sin  t velocity of particle in s.h.m., v = vo cos  t =   )( 22 xxo  electric current, I = A n v q resistors in series, R = R1 + R2+………. resistors in parallel, R 1 = ........11 21  RR electric potential, V = r Q o4 alternating current/voltage, x = xo sin  t magnetic flux density due to a long straight wire, B = dπ2 o Iμ magnetic flux density due to a flat circular coil, B = r2 No Iμ magnetic flux density due to a long solenoid, B = Ion radioactive decay, x = xo exp(–t) decay constant,  = 2 1t 2 ln

©YIJC [Turn over 3 Section A Answer all questions in the spaced provided. 1 Astronauts in space cannot weigh themselves by standing on a bathroom scale. Instead, they measure their mass by oscillating on a large spring. Typically, an astronaut attaches one end of a large spring to his belt and the other end of the spring is hooked to the wall of the space capsule. A fellow astronaut then pulls him away from the wall and releases him. The period T of oscillation of the astronaut is given by 2 mT k where m is the mass of the astronaut and k the force constant of the spring. If T = (3.20  0.01) s and k = (250  5) N m 1, express the mass of the astronaut and its associated uncertainty. Show your working clearly below. mass = ……….………………….. kg [3] [Total: 3]

©YIJC [Turn over 4 2 (a) A student throws a ball, at velocity u, towards a hoop, as shown in Fig. 2.1. The dotted curve represents the path the ball makes. It takes 1.1 s from the point of release to reach the hoop. (i) Determine the vertical component of the initial velocity. vertical component of initial velocity = ………………………. m s1 [2] (ii) Determine the launch angle .  = …………………..  [3] (b) The ball is now thrown in a medium of significant air resistance with the same initial speed and direction. Sketch the new path of the ball in Fig. 2.1. [2] [Total: 7] Fig. 2.1 path

©YIJC [Turn over 5 3 A spring is supported so that it hangs vertically, as shown in Fig. 3.1. Fig. 3.1 Different masses are attached to the lower end of the spring. The extension x of the spring is measured for each mass M. The variation of M with x is shown in Fig. 3.2. Fig. 3.2 (a) With reference to Fig. 3.2, state and explain whether the spring obeys Hooke’s Law. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. …………………………………………………………………………………………….. [2] (b) Describe how to determine whether the spring is permanently deformed after the graph in Fig. 3.2 is obtained. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. …………………………………………………………………………………………….. [1]

©YIJC [Turn over 6 (c) Calculate the work done on the spring as it is extended from x = 40.0 mm to x = 160.0 mm. Explain your working. work done = ……………………. J [3] [Total: 6]

©YIJC [Turn over 7 4 Fig. 4.1 shows two bodies X and Y connected by a light inextensible cord that passes through a frictionless pulley. X starts from rest and moves up a rough plane inclined at 30 ° to the horizontal. The masses of X and Y are 4.0 kg and 5.0 kg respectively. Ignore effects of ai r resistance. Fig. 4.1 Given that the average frictional force acting on X is 10.0 N, when X has travelled 3.0 m along the plane, determine (a) the total kinetic energy of the system, kinetic energy = ……………………. J [3] (b) the speed attained by Y. speed = ……………………. m s1 [1] [Total: 4] Y X 3.0 m pulley rough plane 30

©YIJC [Turn over 8 5 A binary star consists of two stars A and B that orbit about a common centre P, a distance d from the centre of star A, as illustrated in Fig. 5.1. Fig. 5.1 (a) (i) Explain why the centripetal force acting on both stars has the same magnitude. ……………………………………………………………………………………………... ……………………………………………………………………………………………... ……………………………………………………………………………………………... ……………………………………………………………………………………… [2] (ii) The period of the orbit of the stars about point P is 4.0 years. Calculate the angular speed  of the stars.  = ……………………. rad s1 [2]

©YIJC [Turn over 9 (b) The separation of the centres of the stars is 2.8  108 km. The mass of star A is MA. The mass of star B is MB. The ratio of A B M M is 3.0. (i) Determine the distance d. d = ………………………… km [3] (ii) Use your answers in (a)(ii) and (b)(i) to determine the mass MB of star B. Explain your working. MB = ………………………… kg [3] [Total: 10]

©YIJC [Turn over 10 6 A cylindrical tube, seated at one end, has cross -sectional area A and contains some sand . The total mass of the tube and the sand is M. The tube floats upright in a liquid of density ρ, as illustrated in Fig. 6.1. Fig. 6.1 The tube is pushed downwards by a distance of 3.0 cm into the liquid and then released. (a) (i) State the two forces that act on the tube immediately after its release. ……………………………………………………………………………………………... ……………………………………………………………………………………… [1] (ii) State and explain the direction of the resultant force acting on the tube immediately after its release. ……………………………………………………………………………………………... ……………………………………