MSHS 2025 PHY PRELIM P2 QP

[Turn over This document consists of 22 printed pages. Class / Index Number / Centre Number / ‘O’ Level Index Number / Name MARIS STELLA HIGH SCHOOL PRELIMINARY EXAMINATION SECONDARY FOUR PHYSICS 6091/02 Paper 2 Structured and Free Response 28 August 2025 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your class, index number and name on all the work you hand in. 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. Write your answers in the spaces provided. Section B Answer one question. Write your answers in the spaces provided. Circle your choice of question on the cover page. 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 sound use of Physics than for correct answers. The number of marks is given in brackets [ ] at the end of each question or part question. The total marks for this paper (Sections A and B) is 80. For Examiner’s Use Section A 70 Section B ( 11 / 12 ) 10 Total 80

2 Section A Answer all questions in this section. 1 (a) A ball is thrown vertically down towards the ground and rebounds as illustrated in Fig. 1.1. Fig. 1.1 As the ball passes A, it has a speed of 8.4 m s-1. The height of A is 5.0 m above the ground. The ball hits the ground and rebounds to B. Assume that air resistance is negligible. (i) Calculate the speed of the ball just before hitting the ground. speed = ........................................ [2] (ii) Show that the time taken for the ball to reach the ground is 0.46 s. [1]

3 [Turn over (b) The ball rebounds vertically with a speed of 4.2 m s -1 as it leaves the ground. The time the ball is in contact with the ground is 20 ms. The ball rebounds to a maximum height h. The ball passes A at time t = 0. On Fig. 1.2, plot a graph to show how the velocity v of the ball varies with time t. Continue the graph until the ball has rebounded from the ground and reaches B. Fig. 1.2 [3] [Total: 6] 2 Fig. 2.1 shows a 60.0 kg painter on a uniform scaffold of mass 25.0 kg and length 6.0 m, supported from above by ropes at points A and B. A 4.0 kg pail of paint is placed 1.0 m away from one of the supports. Fig. 2.1 paint

4 (a) On Fig. 2.2, draw and label the forces acting on the scaffold. [2] Fig. 2.2 (b) Given that the painter is standing at x = 3.6 m, determine (i) the tension in the rope attached to point B, tension = ........................................ [2] (ii) the tension in the rope attached to point A. tension = ........................................ [2] 4.0 m

5 [Turn over (c) Describe and explain what would happen to the tension in both ropes as the painter walks slowly towards point A on the scaffold. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ......................................................................................................................................... [3] [Total: 9] 3 Fig. 3.1 shows a gas sealed in container using a rubber bung. The container is connected to a mercury manometer. (a) The atmospheric pressure is 76 cm Hg and density of mercury is 13 600 kg/m3. Calculate the pressure of the gas in pascal. Take g as 10 N/kg. pressure = ………………………………[2] 32 cm 15 cm gas rubber bung mercury Fig. 3.1

6 (b) The gas pressure exerted at the rubber bung is equal to the gas pressure exerted at the walls of the container. Explain why this is true, in terms of the particles of the gas. …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………….…. [3] (c) A Physics student notices that small increases in gas pressure are not noticeable enough because the mercury level in the right column of the manometer rises very little. Suggest and explain a change that the student can implement to the manometer so that the rise in level is more noticeable. …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... ……………………………………………………………………………………………….. [2] [Total: 7] 4 Yunnan Guoqiao-mixian (云南过桥米线) is a famous Chinese noodles dish. The first step in preparing this dish is to cook a pot of chicken broth. A pot of water containing chicken is heated over a high flame until it boils. A low flame is then used to keep the soup boiling for 3.0 hours. (a) Explain, in terms of molecules, why the temperature of the boiling soup remains unchanged, even though it is being heated. ..………………………………………………………………………………………………… …………………………………………………………………………………………….… [1]

7 [Turn over (b) (i) The power output of the low flame is 300 W. If 70% of the energy supplied is transferred to the surroundings, calculate the mass of soup that would be vaporized after being heated for 3.0 hours. Assume the specific latent heat of vaporization of the soup is 2.26 × 106 J kg–1. mass of soup vaporized = …………………………. [2] (ii) Explain, in terms of the amount of water molecules remaining in the soup, why it is preferable to use a low flame than a high flame to keep the soup boiling. ………………………………………………………………………………………………… .……………………………………………………………………………………………. [1] (c) As shown in Fig. 4.1, customers ordering the mixian are served with the following: a bowl of hot soup with a layer of oil on the surface, a dish of thin slices of raw meat, and a bowl of pre-cooked mixian (noodles) Fig. 4.1 The meat is first put into the soup. After a while, the mixian is also added. (i) Explain, in terms of thermal processes, why the meat must be sliced into thin pieces. ……………………………………………………………………………………………….. ……………………………………………………………………………………………. [1] (ii) Explain, in terms of thermal processes, the purpose of adding a layer of oil to the bowl. ……………………………………………………………………………………………….. ……………………………………………………………………………………………. [1]

8 (iii) The following data are given: Mass of the soup = 1.0 kg Initial temperature of the soup = 97°C Specific heat capacity of the soup = 4200 J kg–1 K–1 Mass of each slice of meat = 0.020 kg Initial temperature of the meat = 27°C Specific heat capacity of the meat = 3500 J kg–1 K–1 For health reasons, the meat has to be heated to a minimum temper