YSS 2024 4E Phy Prelim P2 with MS

[Turn over YISHUN SECONDARY SCHOOL PRELIMINARY EXAMINATION 2024 SECONDARY 4 EXPRESS CANDIDATE NAME CLASS INDEX NUMBER PHYSICS 6091/02 Paper 2 19 August 2024 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and index number on 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 the question. Write your answers in the spaces provided. 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, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question.

2 This document consists of 23 printed pages.

3 [Turn over Section A Answer all questions. 1 Fig. 1.1 shows an object hanging from the ceiling. The object has a weight of 20 N and it is pulled by a force of 16 N. The figure is not drawn to scale. Fig. 1.1 Using a scale of 1.0 cm : 2.0 N, draw a labelled vector diagram to determine the magnitude of the tension T, in the string. magnitude of tension T = .............................. [3] [total: 3] T 16 N 45

4 2 Fig. 2.1 shows the velocity -time graphs of an object falling in vacuum and in air. The object is dropped from the same height. Fig. 2.1 (a) Define velocity. ………………………………………………………….……………………………………………… ………………..…………………………………….……………………………………………… [1] (b) Calculate the displacement of the falling object in vacuum from t = 1.0 s to t = 1.5 s. displacement = ………………………… [2] (c) The two graphs have different shapes. graph P – in vacuum graph Q - in air velocity m/s time / s 35 30 25 20 15 10 5 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 graph P graph Q

5 [Turn over (i) Describe the acceleration of the object when it is falling in air. ……………………………………………………………………………………….……….. [1] (ii) Explain, using forces acting on the object, the motion of the object you described in (i). ……………………………………………...……………………………………….…………… ……….............................................................................................................................. ……………………………………………………………………….……………………….. [2] (d) State the medium, in vacuum or in air, in which the object has the higher energy in the gravitational potential and kinetic store at t = 3.5 s. higher energy in the kinetic store: ……………………………………………………………….. [1] higher energy in the gravitational potential store: ………………………………………….…. [1] [total: 8]

6 3 Fig. 3.1 shows a Yishunite on a Ferris wheel. The Ferris wheel has eight carriages and has a diameter of 9.6 m. It moves at a uniform speed and it takes 2.0 minutes to make one complete rotation. Fig. 3.1 (a) The Yishunite has a mass of 65 kg. When the Yishunite moves from the lowest to the highest point of the Ferris wheel, determine the change in the energy in the kinetic store, if any, of the Yishunite. change in the energy in the kinetic store = ………………………… [1] (b) Calculate the maximum moment of the weight of the Yishunite about the centre of rotation of the Ferris wheel during the ride. Take g = 10 N/kg. maximum moment of the weight = ………………………… [2] base 9.6 m 7 1 5 2 3 8 6 4

7 [Turn over (c) To ensure the Ferris wheel is stable when it is in operation, the Ferris wheel has a heavy base. Explain how a heavy base improves stability of the Ferris wheel. ………....................................................................................................................................... ………....................................................................................................................................... ………………………………………………..…………………………………………………….. [2] [total: 5] 4 Fig. 4.1 shows an optical fibre used to transmit data by total internal reflection. A ray of light is seen travelling in the optical fibre. Fig. 4.1 (a) State the two conditions for total internal reflection to occur. ………………………………………………..…………………………………………………......…. …………………………………………………..………………………………………………......…. ……………………………………………………..……………………………………………......…. ………………………………………………………………………………………………....…… [2] (b) On Fig. 4.1, complete the path of the ray of light until it emerges at the other end. [1] (c) The optical fibre is light and cheap to produce. State two other advantages of using optical fibres over copper wires in telecommunication. ……………………………………………..……………………………………………………......…. ……………………………………………..……………………………………………………......…. ……………………………………..……….……………………………………......……………... [2] [total: 5] air optical fibre air

8 5 Fig. 5.1 shows three rays of light from the top of an object incident on a converging lens. Fig. 5.1 A sharp image of the object is formed 125 cm on the right side of the lens. (a) On Fig. 5.1, complete the paths of the three incident rays after passing through the lens and draw the sharp image of the object formed. Label the image I. [2] (b) Determine the focal length of the lens. focal length = ………………….……… [1] (c) The tip of the object emits rays of light in all direction. Some of them enter the lens. Most of the rays of light that enter the lens bend at the boundary between air and the lens. However, some rays of light do not bend. Explain why some of the rays of light do not bend when they enter the lens. ……………………………………………………………………………..…………….……….…. [1] [total: 4]

9 [Turn over 6 Fig. 6.1 shows the cooling curves of two metal saucepans. The saucepans contain the same mass of hot water at the same initial temperature. Pan A is white and pan B is black, but otherwise the two saucepans are identical. Both saucepans are uncovered and cool under the same conditions. Fig. 6.1 (a) Explain why pan B cools faster than pan A. …………………………………………………………………………………………………………… ……………………………………………………………………………………………………….. [1] (b) Describe and explain how Fig. 6.1 will be different when the pans are covered and the experiment is repeated. …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… ……………………………………………………………………………………………………….. [2] (c) Explain what is meant by the specific heat capacity of water is 4200 J/(kg °C). …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… ……………………………………………………………………………………………………….. [1] temperature / °C pan A (white) pan B (black) time / minutes

10 (d) The specific heat capacity of water is very high. Suggest one disadvantage of this when water is used for cooking. …………………………………………………………………………………………………………… ………………………………………………………………………………………………………