EJC 2017 J1H2 Promo P2 (Final)

©EJC 2017 9749/02/J1H2PROMO/2017 [Turn over EUNOIA JUNIOR COLLEGE JC1 Promotional Examination 2017 General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CIVICS GROUP 1 7 - REGISTRATION NUMBER PHYSICS Paper 2 Structured Questions 9749/02 03 October 2017 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, civics group and registration number on all the work you hand in. 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 paper clips, highlighters, glue or correction fluid. The use of an approved scientific calculator is expected where appropriate. 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. This document consists of 22 printed pages and 2 blank page. For Examiner’s Use 1 2 3 4 5 6 7 S.F. Total

2 ©EJC 2017 9749/02/J1H2PROMO/2017 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/(36 π)) × 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 ©EJC 2017 9749/02/J1H2PROMO/2017 [Turn over Formulae uniformly accelerated motion, s = ut + ½at2 v2 = u2 + 2as work done on/by a gas, W = pΔV hydrostatic pressure, p = ρgh gravitational potential, φ = Gm r− temperature, T/K = T / oC + 273.15 pressure of an ideal gas, p = 21 3 Nm cV mean translational kinetic energy of an ideal gas molecule E = 3 2 kT displacement of particle in s.h.m. x = xo sin ωt velocity of particle in s.h.m. v = vo cos ωt = ( )22 xxo −±ω electric current, I = Anvq resistors in series, R = R1 + R2 + … resistors in parallel, 1/R = 1/R1 + 1/R2 + … electric potential, V = 4 o Q rπε alternating current/voltage, x = xo sin ωt magnetic flux density due to a long straight wire B = 2 o d µ π I magnetic flux density due to a flat circular coil B = 2 oN r µ I magnetic flux density due to a long solenoid B = onµ I radioactive decay, x = xo exp (–λt) decay constant λ = 1 2 ln2 t

4 ©EJC 2017 9749/02/J1H2PROMO/2017 1 During a war, a helicopter was travelling at a velocity of 20.0 m s -1 at an angle of 30° above the horizontal as shown in Fig. 1.1. Fig. 1.1 (a) Neglecting the effects of air resistance, determi ne the vertical component of the velocity of the helicopter, uy. magnitude of uy = ……………….. m s-1 [1] (b) A bomb was dropped from the helicopter. (i) Determine the vertical displacement, from the point of release , that the bomb falls 4.0 s after it was released, assuming that it has yet to hit the ground. vertical displacement = ……………….. m [1] (ii) Hence, determine the distance of the bomb from the helicopter 4.0 s after it was released. distance from helicopter = ……………….. m [1] flat ground

5 ©EJC 2017 9749/02/J1H2PROMO/2017 [Turn over (c) To ensure that the enemy is wiped out completely, the pilot dropped a second bomb 2.0 s after the first. (i) On the axis provided on Fig. 1.2, sketch a graph showing how of the vertical component of velocity vy of the first bomb varies against time t, for the first 5 s after the bomb was released. Take t = 0 s to be the time of release of the first bomb. Label this graph A. [2] (ii) On the same axis on Fig. 1.2, sketch a graph showing how of the vertical component of velocity vy of the second bomb varies against time t in this same time period. Label this graph B. [1] Appropriate values should be indicated. Fig. 1.2 (d) Using your answer to (c ) or otherwise, calculate the vertical distance of the second bomb above the first bomb 3.0 s after the second bomb was released. distance = ……………….. m [2] t / s vy / m s-1

6 ©EJC 2017 9749/02/J1H2PROMO/2017 (e) State and explain whether the 2 bombs are going to hit the same spot when it eventually lands on the flat ground. [2] 2 (a) State the principle of conservation of momentum. [1] (b) Block A, of mass 2.0 kg, has a light spring attached to it as shown in Fig. 2.1. Block B has a mass of 5.0 kg and is initially at rest. Fig. 2.1 Block A moves with a velocity of 3.5 m s -1 over the frictionless surface towards Block B and the two blocks undergo a head-on, elastic collision, during which the spring on block A is compressed as shown in Fig. 2.2. Fig. 2.2 At a certain time during this collision, the two blocks A and B have a common velocity vo. (i) Determine the value of vo. magnitude of v o = ……………….. m s-1 [1] B A 3.5 m s-1 B A

7 ©EJC 2017 9749/02/J1H2PROMO/2017 [Turn over (ii) Hence, calculate the total kinetic energy of the system during this time. kinetic energy = ……………….. J [1] (iii) Explain how is it possible that the answer to (b)(ii) is less than t he initial kinetic energy of A. [1] (c) Blocks A and B separate after the collision in (b). Determine the magnitude of the velocities vA and vB of blocks A and B respectively after collision. v A = ……………….. m s-1 [4] v B = ……………….. m s-1 [4]

8 ©EJC 2017 9749/02/J1H2PROMO/2017 3 Fig. 3.1 shows a side view of a bathroom wall cabinet. Its lower edge rests against the wall at A. It is fastened by screws at a height h vertically above A. The mass of the cabinet is 10 kg and its centre of gravity is 0.15 m from the wall. Fig. 3.2 shows the free body diagram for the cabinet. Fig. 3.1 Fig. 3.2 (a) State the magnitude of force Y. magnitude of Y = ……………….. N [1] (b) Explain why forces X and P must have equal magnitude. [1] (c) Calculate the magnitude of force X when h = 0.60 m. magnitude of X = ……………….. N [2] 0.15 m h C.G. screw A Q X Y P

9 ©EJC 2017 9749/02/J1H2PROMO/2017 [Turn over (d) In principle, the fixing screws could be positioned anywhere between point A and the top of the cabinet. Sketch on the axis provided in Fig. 3.3, a graph to show how the magnitude of force X would vary for the values of h from zero up to 0.60 m. [1] Fig. 3.3 X h 0

10 ©EJC 2017 9749/02/J1H2PROMO/2017 4 A cylinder and piston used in a car engine is as shown in Fig. 4.1. Fig. 4.1 The vertical oscillation of the piston in the cylinder can be assumed to be simple harmonic. The top surface of the piston in the cylinder is at AB when it is at its lowest position and at CD when it is at its highest position as marked in Fig. 4.1. (a) Explain what it means when the oscillation of the piston is simple harmonic. [2] (b) At a particular engine speed, the displacement d of the piston may be represented by the equation ( )4.0cos 220dt= − where d is measured in centimetres. (i) State the distance between the lowest position AB and the highest position CD of the top surface of the piston. distance = ……………….. cm [1]