2013_NYJC_H2_Physics_P2_Answer

© NYJC 2013 JC2/Prelim/H2/9646/02 [Turn over NANYANG JUNIOR COLLEGE Science Department JC 2 PRELIMINARY EXAMINATION Higher 2 Candidate Name Class Tutor Name PHYSICS 9646/02 Paper 2 Structured Questions 24 September 2013 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and tutor name 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. Answer all questions. 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. For Examiner’s Use 1 2 3 4 5 6 7 8 Total This document consists of 20 printed pages Nanyang Junior College

2 © NYJC 2013 JC2/Prelim/H2/9646/02 Data Formulae uniformly accelerated motion, s = ut + ½at2 v2 = u2 + 2as work done on/by a gas, W = pΔV hydrostatic pressure, p = Ρgh gravitational potential,  = /Gm r displacement of particle in s.h.m. x = xo sin ωt velocity of particle in s.h.m. v = vo cos ωt =  22 xxo   mean kinetic energy of a molecule of an ideal gas E = 3 2 kT resistors in series, R = R1 + R2 + … resistors in parallel, 1/R = 1/R1 + 1/R2 + … electric potential, V = Q / 4πεor alternating current/voltage, x = xo sin ωt transmission coefficient, T α exp(-2kd) where k =   2 2 8 m U E h   radioactive decay, x = xo exp (-λt) decay constant λ = 21 693.0 t speed of light in free space, c = 3.00 x 108 m s-1 permeability of free space, μo = 4π x 10-7 H m-1 permittivity of free space, εo = 8.85 x 10-12 Fm-1 (1 / (36 π)) x 10-9 Fm-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

3 © NYJC 2013 JC2/Prelim/H2/9646/02 [Turn over For Examiner’s Use 1 (a) State the relation between force and momentum. …………………………………………………………………………………………….. [1] (b) A rigid bar of mass 450 g is held horizontally by two supports A and B, as shown in Fig. 1.1. Fig. 1.1 The support A is 45 cm from the centre of gravity C of the bar and the support B is 25 cm from C. A ball of mass 140 g falls vertically onto the bar such that it hits the bar at a distance of 50 cm from C, as shown in Fig. 1.1. The variation with time of the velocity of the ball before, during and after hitting the bar is shown in Fig. 1.2. Fig. 1.2