2023 ACSBR Phy Prelims P2

Name: Class: Class Index No.: Anglo-Chinese School (Barker Road) PRELIMINARY EXAMINATION 2023 SECONDARY FOUR EXPRESS PHYSICS 6091 PAPER 2 TIME: 1 HOUR 45 MINUTES READ THESE INSTRUCTIONS FIRST Write your name, class & exam index number in the box provided at the top of this page. Write in dark blue or black pen. You may use a pencil for any diagrams or graphs. Do not use glue or correction fluid. Section A Answer all questions. Section B Answer all questions. Question 13 has a choice of parts to answer. Candidates are reminded that all quantitative answers should include appropriate units. The use of an approved scientific calculator is expected, where appropriate. Candidates are advised to show all their working in a clear and orderly manner, as more marks are awarded for the sound use of Physics than correct answers. The number of marks is given in brackets [ ] at the end of each question or part question. This question paper consists of 24 printed pages. For Examiner’s Use Section A Section B Total / 80

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 2 Secondary 4 Express Physics 6091/02 SECTION A (50 marks) Answer all the questions in this section. 1 Fig. 1.1 shows a 58 g ball being thrown vertically upwa rds from the top of a building with an initial velocity of 20 m/s. It reaches the highest point and begins to fall. It lands on the ground when time is 6.0 s. The velocity-time graph is shown in Fig. 1.2. Air resistance is negligible. (a) Explain how Fig. 1.2 shows that the ball is moving in the opposite direction after a period of time. ……………………………………………………………………………................................. ……………………………………………………………………………................................. [1] (b) Determine the time t for the ball to reach its highest point. t = ………………………… [1] (c) Calculate the velocity v of the ball just before it touches the ground. v = ………………………… [1]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 3 Secondary 4 Express Physics 6091/02 (d) Calculate the height h of the building. h = ………………………… [2]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 4 Secondary 4 Express Physics 6091/02 2 Fig. 2.1 shows a car being lifted by two ropes . Th e car remains horizontal and moves vertically upwards at a constant speed. Fig. 2.1 The weight of the car is 18 000 N and the tension s in rope 1 and rope 2 are T 1 and T 2 respectively. (a) State the two conditions for the car to be in a state of equilibrium while it is moving upwards at a constant speed. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. …………………………………………………………………………………………………. [2] (b) Taking moments about the rear wheel, calculate T1 and T2. T1 = …………………………. T2 = …………………………. [3]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 5 Secondary 4 Express Physics 6091/02 3 Fig. 3.1 shows a manometer joined to a cylinder containing a gas. The piston has a cross - sectional area of 0.012 m2. Fig. 3.1 Atmospheric pressure is 100 kPa. The pressure exerted by the piston on the gas is 140 kPa. Force F is the force of the piston acting on the gas. Calculate (a) the force F, F = ………………………… [2] (b) the density of the liquid. density = ………………………… [2] F

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 6 Secondary 4 Express Physics 6091/02 (c) With the same force F still exerting on the piston, the gas in the cylinder is now heated. It is observed that the piston moves to the left. Explain, using ideas about molecules, why the piston moves to the left. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… [3]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 7 Secondary 4 Express Physics 6091/02 4 Fig. 4.1 shows a 0.50 kg ball sliding down a rough incline from position A which is 7.5 m above the ground with an initial speed of vo. Friction along the incline produces 10.7 J of heat energy. The ball leaves the incline at position B moving vertically upward and reaches a height of 13.0 m above the ground at position C. Fig. 4.1 (a) State the principle of conservation of energy. ………………………………………………………………………………….……………… ………………………………………………………………………………….……………… [1] (b) (i) Calculate the gravitational potential energy of the ball at position C. Take gravitational field strength g is 10 N/kg. gravitational potential energy = …………………. [2] (ii) Calculate the initial speed v0, at position A. v0 = …………………. [2] 13.0 m 7.5 m v0 C B A

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 8 Secondary 4 Express Physics 6091/02 (c) State one assumption for your calculations in (b)(ii). …………………………………………………………………………………………….…… …………………………………………………………………………………………….…… [1]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 9 Secondary 4 Express Physics 6091/02 5 In a company that manufactures frying pans, a researcher wishes to select a new material that can be used for the base of the pan. Fig. 5.1 shows four possible materials and their properties. material melting point / °C specific heat capacity / J/(kg °C) A 2350 900 B 950 480 C 1600 480 D 7800 130 Fig. 5.1 (a) (i) The researcher carries out a series of experiments on the materials. In one of the experiments, a 2 kg sample of material A is heated by an electrical heater of power 450 W. The initial temperature of the sample is 25 °C. Calculate the time taken for the temperature of the sample to rise to 100 °C. time taken = ………………………………… [2] (ii) Using the data in Fig. 5.1, discuss which material is the most suitable to be used for the base of the frying pan. Give two reasons to support your choice. ……………………………………………………………………………………….......... ……………………………………………………………………………………….......... ……………………………………………………………………………………….......... ……………………………………………………………………………….…………..... [2] (b) 2.3 kg of hot water at boiling point is poured into the frying pan. 5 190 000 J was supplied to convert all the water into steam at boiling point. Calculate the specific latent heat of vaporisation of water. specific latent heat of vaporisation= ………………………………….. [1]

Anglo-Chinese School (Barker Road) Preliminary Examination 2023 10 Secondary 4 Express Physics 6091/02 6 In Fig. 6.1 th