2013 IJC H2 Physics P2

© IJC 2013 9646/Prelim2/02/13 [Turn over INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION 2 in preparation for General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CLASS INDEX NUMBER PHYSICS Paper 2 Structured Questions Candidates answer on the Question Paper No Additional Materials are required. 9646/02 16 September 2013 1 hour 45 minutes READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. For Section A Answer all questions. It is recommended that you spend about 1 hour and 15 minutes on this section. For Section B Answer Question 8. It is recommended that you spend about 30 minutes on this section. At the end of the examination, fasten all your work securely together. The number of marks is given in the brackets [ ] at the end of each question or part question. This document consists of 24 printed pages. For Examiner’s Use 1 6 2 10 3 8 4 8 5 6 6 7 7 15 8 12 Significant Figures Total 72 Innova Junior College [Turn over

2 © IJC 2013 9646/Prelim2/02/13 [Turn over For Examiner’s Use Data speed of light in free space, c = 3.00 x 108 m s-1 permeability of free space, o = 4 x 10−7 H m−1 permittivity of free space, o = 8.85 x 10−12 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 t 2 v2 = u2+ 2as work done on/by a gas, W = pV mean kinetic energy of a molecule of an ideal gas E = kT2 3 hydrostatic pressure, p = gh gravitational potential,  = GM r displacement of particle in s.h.m. x = xosin ωt velocity of particle in s.h.m. v= v ocos ωt   22 ox x  resistors in series, R= R 1 + R2 + … resistors in parallel, 1/R = 1/R 1 + 1/R2 + … electric potential V = Q/4or alternating current/voltage, x = xo sint transmission coefficient T = exp ( −2kd) where k =  2 2 8 mU E h   radioactive decay, x = xo exp(−t) decay constant,  = ½ 0.693 t

3 © IJC 2013 9646/Prelim2/02/13 [Turn over For Examiner’s Use Section A Answer all the questions in this section. 1 A stone is being thrown from the top of the cliff with velocity 13 m s 1 at 50 o to the horizontal as shown in Fig. 1.1. Fig. 1.1 (a) On the axes of Fig. 1.2, ignoring air resistance, draw and label graphs to represent the variation with time of (i) VH, the horizontal component of the velocity, (ii) VV, the vertical component of the velocity of the stone. Take upwards as positive direction. [3] Fig. 1.2 (b) Using your answer in (a), calculate the maximum vertical height h of the stone above its point of projection. h = …………………………….. m [1] cliff 50o 13 m s1 Velocity / m s1 time / s 1.0 2.0 3.0 0 10 10 20 20

4 © IJC 2013 9646/Prelim2/02/13 [Turn over For Examiner’s Use (c) State and explain how the value in (b) will be affected if air resistance is considered. [2]

5 © IJC 2013 9646/Prelim2/02/13 [Turn over For Examiner’s Use 2 (a) A moon is in a circular orbit of radius r about a planet. The planet and its moon may be considered to be point masses that are isolated in space. Show that, for the moon in circular orbit, the period T of the orbit is given by the expression T 2 =  r3 where  is a constant. Explain your working. [3] (b) Phobos and Deimos are moons that are in circular orbits about the planet Mars. Data for Phobos and Deimos are shown in Fig. 2.1. Moon Radius of orbit / 10 6 m Period of rotation about Mars / hours Phobos 9.39 7.65 Deimos 19.9 T Fig. 2.1 (i) Using the expression in (a) and the data from Fig. 2.1, determine the period of Deimos, T, in its orbit about Mars. T = ……………………………. hours [2] (ii) The period of rotation of Mars about its axis is 24.6 hours. Deimos is in an equatorial orbit, orbiting in the same direction as the spin of Mars about its axis. Use your answer in (i) to comment on the orbit of Deimos. [1]

6 © IJC 2013 9646/Prelim2/02/13 [Turn over For Examiner’s Use (c) A binary star consists of two stars that orbit about a fixed point C, as shown in Fig. 2.2. Fig. 2.2 The star of mass M1 has a circular orbit of radius R1 and the star of mass M2 has a circular orbit of radius R2. Both stars have the same angular speed , about C. (i) State the formula, in terms of G, M1, M2, R1, R2 and for 1. the gravitational force between the two stars, [1] 2. the centripetal force on the star of mass M1. [1] (ii) Suggest why M1 is of a bigger mass compared to M2. [2]

7 © IJC 2013 9646/Prelim2/02/13 [Turn over For Examiner’s Use 3 (a) State the first law of thermodynamics. [2] (b) Fig. 3.1 shows two isothermal p−V graphs for a fixed mass of an ideal gas trapped in a cylinder by a piston. Fig. 3.1 (i) Isotherm A is for a temperature of 340 K. Calculate the temperature for isotherm B. Show your reasoning clearly. temperature = ……………………………. K [2]

8 © IJC 2013 9646/Prelim2/02/13 [Turn over For Examiner’s Use (ii) The gas is taken around the cycle of changes PQRSP shown by the arrows on Fig. 3.1. Use the graph to estimate the net work done during the cycle. work done = ……………………………. J [2] (iii) Hence determine the net heat supplied to the gas during the cycle. net heat supplied = ……………………………. J [2]

9 © IJC 2013 9646/Prelim2/02/13 [Turn over For Examiner’s Use 4 A mass M is moving at a speed of 5.00 m s −1 along a horizontal frictionless guide which bends into a vertical circle of radius r, as illustrated in Fig. 4.1. Fig. 4.1 Fig. 4.2 shows the the variation of the horizontal velocity of the mass with time along the section ABC of the curve. Fig. 4.2

10 © IJC 2013 9646/Prelim2/02/13 [Turn over For Examiner’s Use (a) (i) Using the principle of conservation of energy and with the aid of Fig. 4.2, find an appropriate value for the height of the vertical circle. height of vertical circle = ……………………………. m [2] (ii) Hence, find the value for the radius r of the vertical circle. radius of vertical circle = ……………………………. m [1] (iii) Show that the minimum speed vc for the mass M to remain in contact with the track when it is at point C is , where g is the acceleration of free fall. [2]