2021 Prelim Phy P3

Name : Centre/Index Number: Class: DUNMAN HIGH SCHOOL Preliminary Examination Year 6 H2 PHYSICS Paper 3 Longer Structured Questions Candidates answer on the Question Paper 9749/03 23 September 2021 2 hours READ THESE INSTRUCTIONS FIRST Write your centre number, index number, name and class at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions. Section B Answer any one question. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. The number of marks is given in brackets [ ] at the end of each question or part question. © DHS 2021 9749/03 [Turn over This document consists of 25 printed pages and 1 blank page. This document consists of 23 printed pages and 1 blank page. For Examiner’s Use Section A 1 10 2 8 3 9 4 5 5 8 6 7 7 13 Section B 8 / 9 20 Total 80

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 © DHS 2021 9749/03 [Turn over

3 Formulae uniformly accelerated motion, s = ut + 1 2 at2 v2 = u2 + 2as work done on/by a gas, W = pV hydrostatic pressure, p = gh gravitational potential,  = −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 = kT2 3 displacement of particle in s.h.m., x = x0 sin t velocity of particle in s.h.m., v = v0 cos t =  22 xxo  electric current, I = Anvq resistors in series, R = R1 + R2 + . . . resistors in parallel, 1/R = 1/R1 + 1/R2 + . . . electric potential, V = r Q o4 alternating current / voltage, x = x0 sin t magnetic flux density due to a long straight wire, B = 0 2 d I  magnetic flux density due to a flat circular coil, B = 0 2 N r I magnetic flux density due to a long solenoid, B = 0nI radioactive decay, x = x0 exp(t) decay constant,  = 1 2 ln2 t © DHS 2021 9749/03 [Turn over

4 © DHS 2021 9749/03

5 Section A Answer all the questions in this section in the spaces provided. 1 (a) Explain what is meant by acceleration. ……….…………………………………………………………………………………………….[1] (b) A ball is kicked from horizontal ground towards the top of a vertical wall, as shown in Fig. 1.1. The horizontal distance between the initial position of the ball and the base of the wall is 24 m. The ball is kicked with an initial velocity v at an angle of 28° to the horizontal. The ball hits the top of the wall after a time of 1.5 s. Air resistance may be assumed to be negligible. (i) Calculate the initial horizontal component vX of the velocity of the ball. vX = ……………………m s–1 [1] (ii) Show that the initial vertical component vY of the velocity of the ball is 8.5 m s–1. [1] © DHS 2021 9749/03 [Turn over path of ball v wallball Fig. 1.1 (not to scale) 28o horizontal ground 24 m Fig. 1.1 (not to scale)

6 (iii) Calculate the time taken for the ball to reach its maximum height above the ground. time = …………………… s [2] (iv) The ball is kicked at time t = 0. On Fig. 1.2, sketch the variation with time t of the vertical component vY of the velocity of the ball until it hits the wall. It may be assumed that velocity is positive when in the upward direction. [2] (c) Determine the maximum height of the ball above the ground. maximum height = …………………… m [2] © DHS 2021 9749/03 vY / m s-1 Fig. 1.2

7 (d) A ball of greater mass is kicked with the same velocity as the ball in (b). State and explain the effect, if any, of the increased mass on the maximum height reached by the ball. Air resistance is still assumed to be negligible. ………………………………………………………………………………………..……………... ………………………………………………………….……………………………………….. [1] 2 (a) Explain what is meant by weight. ………………………………………………………………………………………..……………... ………………………………………………………….……………………………………….. [1] (b) Fig. 2.1 shows a system of two pulleys with one pulley fixed to the ceiling but free to rotate. The other pulley is attached to a load. Fig. 2.1 (not to scale) A force is used to pull the free end of the rope and this lifts the load at a constant speed. The air resistance and friction are negligible. The moving pulley has a mass of 2.40 kg and the load is a box of weight 960 N. © DHS 2021 9749/03 [Turn over ceiling fixed pulley rope 11.5o force 11.5o moving pulley load

8 (i) The tension T in the rope is constant along its length. Calculate the tension T. T = …………………… N [3] (ii) As the rope moves upwards, the tension in the rope changes. Explain how the tension changes. ….. ……………………………………………………………………………………………..... .….……………………………………………………………………………………………. [2] (c) When the pulley system is used, the work done by the force is greater than the gravitational potential energy gained by the load. (i) Suggest one reason for this. ….. ……………………………………………………………………………………………..... .….……………………………………………………………………………………………. [1] (ii) Suggest one advantage for using the pulley system. © DHS 2021 9749/03

9 ….. ……………………………………………………………………………………………..... .….……………………………………………………………………………………………. [1] 3 The volume of air in the cylinder of a car engine is 540 cm3 at a pressure of 1.1 x 105 Pa and a temperature of 27 oC. The air is suddenly compressed to a volume of 30 cm 3. No heat energy enters or leaves the gas during the compression. The pressure then rises to 6.5 x 10 6 Pa. Assume that air behaves as an ideal gas. (a) Determine the temperature of the gas after the compression. temperature = …………………… K [2] (b) (i) State the first law of thermodynamics. …………………………………………………………………………………..……………... .…………………………………………………….……………………………………….. [2] (ii) Use the law to explain why the temperature of the air changes during compression. …………………………………………………………………………………..……………... .…………………………………………………….…………………………………………… …………………………………………………………………………………..……………... …………………………………………………………………………………..……………... .…………………………………………………….……………………………………….. [3] © DHS 2021 9749/03 [Turn over

10 (c) The temperature of a gas depends on the root-mean-square (r.m.s.) speed of its molecules. Calculate the ratio: r.m.s. speed of gas molecules at 350 K r.m.s. speed of gas molecules at 300 K ratio = …………………… [2] © DHS 2021 9749/03