CWSS 2026 Physics Prelim P2 QP

COMMONWEALTH SECONDARY SCHOOL PRELIMINARY EXAMINATION 2026 SECONDARY 4 EXPRESS PHYSICS Name: ________________________________________( ) Class: ___________ Physics 6091/02 Paper 2 Theory Candidates answer on the Question Paper. No Additional Materials are required. Monday 31 August 2026 1130 – 1315 1 hour 45 minutes READ THESE INSTRUCTIONS FIRST Write your name, index number and class on the question paper and any separate answer sheets used. 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 one question. 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. At the end of the examination, ensure that you have submitted all your work. The number of marks is given in brackets [ ] at the end of each question or part question. 80 Name of setter: Mdm Quek Lay Hong This booklet consists of 20 printed pages and 2 blank pages.

2 Do not write in this margin SECTION A Answer all the questions in this section. 1 (a) State the principle of moments. …………………………………………………………………………………………….. …………………………………………………………………………………………….. ………………………………………………………………………………………….[2] (b) Fig. 1.1 shows a metal sheet suspended from a hole in one corner at A. The weight of the metal is 0.50 N and the centre of gravity is at B. The diagram is drawn to full scale. Fig. 1.1 (to scale) (i) State what is meant by the centre of gravity is at B. ……………………………………………………………………………………. ………………………………………………………………………………….[1] (ii) Using a measurement taken from Fig. 1.1, calculate the moment of the weight about point A. On Fig. 1.1, indicate the measurement that you make. moment = ……………………. [3] Weight 0.50 N

3 Do not write in this margin (iii) The metal sheet in Fig. 1.1 swings freely and eventually comes to rest. Describe the final position of B and explain why the sheet remains at rest in this position. ……………………………………………………………………………………. ……………………………………………………………………………………. ………………………………………………………………………………….[2] [Total: 8]

4 Do not write in this margin 2 (a) A car of mass 970 kg is travelling at 27 m/s when the brakes are applied. The speed of the car decreases to 15 m/s in 40 m. (i) Calculate the amount of energy that is transferred out of the kinetic store of the car when the brakes are applied. energy transferred out = …....…………….… [2] (ii) Hence, calculate the magnitude of the average braking force on the car. average braking force = …………..……….… [2] (b) One type of renewable energy source is shown in Fig. 2.1. Fig 2.1 (i) State the name of the renewable energy source shown in Fig. 2.1. ................................................................................................................. [1] (ii) State what is meant by a renewable energy source. ..................................................................................................................... ...................................................................................................................[1] [Total: 6] metal pipes hot water and steam up Earth’s surface cold water down cracks in hot rocks

5 Do not write in this margin 3 A man uses a steam wallpaper stripper, shown in Fig. 3.1, to help him prepare his living room for re-decoration. Fig. 3.1 When the appliance is in use, water is heated until it boils and produces steam. The plate is then held against the wall and the steam released from the pipe slackens the wallpaper, releasing it from the wall. The following information is shown on the appliance: IMPORTANT: Ensure that the metal tank is fully filled before switching current on. Power rating 2.5 kW Voltage 240 V Capacity 20 litres Tap water at 20 oC is used to fill the tank. One litre of water has a mass of one kilogram. The stripper is used until 50% of the water has been turned into steam. The specific heat capacity of water is 4200 J/(kg oC) and the s pecific latent heat of vaporisation of water is 2.26 x 106 J/kg. (a) Define specific heat capacity. …………………………………………………………………………………..…………... …………………………………………………………………………………..……….….. …………………………………………………………………………….……..….…… [2]

6 Do not write in this margin (b) Calculate the energy transferred to heat the water to 100 oC. energy transferred = ……….……………...… [1] (c) Define specific latent heat of vaporisation. ………………………………………………………………………..….………………….. ………………………………………………………………………..….………………….. ………………………………………………………………………..….…………….… [2] (d) Calculate the energy transferred to turn 50% of water at 100 oC into steam. energy transferred = ………….…………….… [1] (e) Determine the time for which the stripper was switched on. time taken = ……….……...…………..…….… [2] (f) Explain why the time determined in (e) is shorter than the actual time for which the stripper was switched on. ................................................................................................................................... ...............................................................................................................................[1] [Total: 9]

7 Do not write in this margin 4 Fig. 4.1 shows 11 toy boats floating on water. The boats are stationary and spaced 5.0 cm apart from each other. Fig. 4.2 shows a dipper P connected to a motor that vibrates with a frequency of 10 Hz. The positions of the boats are shown at an instant in Fig. 4.2. (a) Determine the (i) wavelength wavelength = ……..……….………...……… [1] (ii) speed speed = ………………….…..……….………. [2] (iii) amplitude of the wave. amplitude = …………………..…..…………. [1] (b) State the direction of motion of A, D and G in the next instant of time. A: ………………………… D: ……………………… G: ………………………… [2] [Total: 6] 2.0 cm Fig. 4.1 Fig. 4.2

8 Do not write in this margin 5 (a) Fig. 5.1 shows an eye of an observer and an object in front of a plane mirror. The object is marked with x. Fig. 5.1 Draw a ray on Fig. 5.1 to show how the eye sees the object in the mirror. Label the image I. Show all essential construction work clearly. [2] (b) Fig. 5.2 shows a ray of light travelling from air into a transparent block made from substance X. Fig. 5.2 (i) Define refractive index.