2024 ACSBR Physics Prelim P2

Name: Class: Index No.: Anglo-Chinese School (Barker Road) PRELIMINARY EXAMINATION 2024 SECONDARY FOUR EXPRESS PHYSICS 6091 PAPER 2 TIME: 1 HOUR 45 MINUTES READ THESE INSTRUCTIONS FIRST Write your name, class & 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 one question only. Question 15 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 / 70 Section B / 10 Total / 80

Anglo-Chinese School (Barker Road) Preliminary Examination 2024 2 Secondary 4 Express Physics 6091/2 SECTION A (70 marks) Answer all the questions in this section. 1 Fig. 1.1 is the speed-time graph for a rocket from the moment that the fuel starts to burn at time t = 0. Fig. 1.1 (a) State the magnitude of the acceleration of the rocket at t = 0. acceleration = ……………………….. [1] (b) Describe the motion of the rocket between t = 5 s and t = 80 s. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. [2] (c) Calculate the acceleration of the rocket at t = 90 s. acceleration = ……………………….. [2]

Anglo-Chinese School (Barker Road) Preliminary Examination 2024 3 Secondary 4 Express Physics 6091/2 2 A rock climber, of total weight 620 N, holds herself in equilibrium against a vertical cliff. She pulls on a rope that is fixed at the top of the cliff and presses her feet against the cliff. Fig. 2.1 shows her position. Fig. 2.1 The climber’s centre of gravity is 0.90 m from the cliff. (a) Calculate the moment due to her weight about her feet. moment = …………………….. [1] (b) The rope is at an angle to the horizontal and the distances are as shown in Fig. 2.1. Determine the tension in the rope. tension = ……………….. [2]

Anglo-Chinese School (Barker Road) Preliminary Examination 2024 4 Secondary 4 Express Physics 6091/2 3 Fig. 3.1 shows a mercury manometer. The left arm of the manometer contains some trapped gas. The density of mercury is 13 600 kg/m3. The gravitational field strength g is 10 N/kg. Fig. 3.1 (a) (i) The atmospheric pressure is 76.0 cm Hg. Calculate this pressure in Pascals. pressure = …………………….. [1] (ii) Calculate the pressure of the trapped gas. Calculate this pressure in Pascals. pressure = ……………………….. [2]

Anglo-Chinese School (Barker Road) Preliminary Examination 2024 5 Secondary 4 Express Physics 6091/2 (b) A small hole is discovered in the left arm of the manometer such that the trapped gas can escape to the surroundings. By drawing on Fig. 3.2, indicate the new mercury levels in both arms of the manometer. Fig. 3.2 [1]

Anglo-Chinese School (Barker Road) Preliminary Examination 2024 6 Secondary 4 Express Physics 6091/2 4 A plastic tray has fifteen sections as shown in the Figure 4.1 below. Fig. 4.1 When it is filled with water and placed in the freezer compartment of a refrigerator, the water freezes to form ice cubes. (a) Describe the change(s), if any, that occur(s) to the arrangement and to the motion of the molecules as the water becomes ice. arrangement: …………………………………………………………………………………… ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. motion: ………………………………………………………..…………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. [2] (b) Each section contains a mass of 20 g of water that is initially at a temperature of 28 °C. The specific latent heat of fusion of ice is 330 J/g and the specific heat capacity of water is 4200 J/(kgºC). (i) Define specific heat capacity. ……………………………………………………………………………………………. ……………………………………………………………………………………………. [1]

Anglo-Chinese School (Barker Road) Preliminary Examination 2024 7 Secondary 4 Express Physics 6091/2 (ii) Calculate the total amount of energy released from the water for all the water in the tray to become ice at 0 ºC. energy = …………………….. [3] (iii) The freezer compartment takes energy from the water at a rate of 30 W. Calculate the time taken for all the water in the tray to become ice. time taken = ………………….. [2]

Anglo-Chinese School (Barker Road) Preliminary Examination 2024 8 Secondary 4 Express Physics 6091/2 5 Fig. 5.1 shows the horizontal forces as a cyclist travels forward. Fig. 5.1 The cyclist produces the driving force that acts on the back wheel. As the bicycle moves, energy is transmitted from the pedals to the back wheel. Fig. 5.2 shows what happens to the energy input to the pedals. Fig. 5.2 (a) State the principle of conservation of energy. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. [2] (b) Calculate the efficiency of the bicycle in transmitting energy from the pedals to the back wheel.