62 2021 BPGH 4E Prelim PHY P2

This paper consists of 27 printed pages and 1 blank page. Name of Candidate: ____________________ ( ) Class: _________ Calculator Model: BUKIT PANJANG GOVERNMENT HIGH SCHOOL PRELIMINARY EXAMINATION 2021 SECONDARY 4 EXPRESS PHYSICS Paper 2 Theory Candidates answer on the Question Paper. No additional materials are required 6091/02 Date: 23 Aug 2021 Duration: 1 hr 45 min Time: 1100 – 1245 h READ THESE INSTRUCTIONS FIRST Write your name, register number and class on all the work you hand in. Write in dark blue or black ink on both sides of the paper. You may use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A Answer all questions. Section B Answer all questions. Question 11 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 al l 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. For Examiner’s Use Section A For Examiner’s Use 1 5 Section A Total [50] 2 6 Section B Total [30] 3 7 Overall Total [80] 4 8 Setter: Mdm Chee Wei Wei [Turn over

2 ©BPGHS 2021 6091 / SEC 4 EXP PHY PRELIM / P2 [Turn over Section A (50 marks) Answer all the questions in this section. 1 A motor boat travels due north at a steady speed of 3.0 m/s through calm water in which there is no current as shown in Fig. 1.1. (a) Explain how the first statement gives information not only about the speed of the boat but also about its velocity. .................................................................................................................................... ................................................................................................................................ [1] (b) The boat then enters an area of water in which a steady curr ent flows at 2.0 m/s in a south-west direction as shown in Fig. 1.2. Both the engine power of the boat and its course setting remain unchanged. Draw a vector diagram to determine the magnitude and direction of the resultant velocity of the boat. magnitude = ………………… direction =………………………………. [3] N 3.0 m/s Fig. 1.1 45 current 2 m/s Fig. 1.2 boat N

3 ©BPGHS 2021 6091 / SEC 4 EXP PHY PRELIM / P2 [Turn over 2 A water wheel has eight buckets equally spaced around its circumference, as illustrated in Fig. 2.1. The distance between the centre of each bucket and the centre of the wheel is 1.6 m. When a bucket is at its highest point, it is filled with 40 kg of wat er. The wheel rotates and the bucket is emptied at its lowest point. The gravitational field strength is 10 N/kg. Fig. 2.1 (a) (i) Define the moment of a force. …..…................................................................................................................... ….................................................................................................................... [1] (ii) Write down the numbers of those buckets containing water that cause a moment about the axle at the instant shown in Fig. 2.1. buckets: ……………………………… [1] (iii) Determine the largest moment provided by the bucket filled with water about the axle of the wheel. largest moment = ………………………… [2] empty bucket water full bucket direction of rotation 1.6 m water

4 ©BPGHS 2021 6091 / SEC 4 EXP PHY PRELIM / P2 [Turn over 3 Fig. 3.1 shows a liquid-in-glass thermometer. Fig. 3.1 (a) Describe how to check that the upper fixed point is marked correctly on the thermometer. ……............................................................................................................................... ……............................................................................................................................... …................................................................................................................................... ……........................................................................................................................... [2] (b) The thermometer makes use of the change in volume of a liquid to measure temperature. In the table below, name one other physical property that is used to measure temperature, and the substance or object involved. physical property that changes substance or object involved example volume a liquid [1] (c) The thermometer has a heat capacity of 2.5 J /C and initially reads 20 C. The thermometer is placed in a small mass of water which is initially at a temperature of 90 C. The final temperature of the water and the thermometer is 82 C. The specific heat capacity of water is 4.2 J / (gC). Determine the mass of water. mass = ………………........ [2]

5 ©BPGHS 2021 6091 / SEC 4 EXP PHY PRELIM / P2 [Turn over 4 The floor of a swimming pool always appears shallower than its actual depth due to the refraction of light. Fig. 4.1 shows the image of a line on the floor of the pool as appeared to the eye looking directly above the surface of the pool. Fig. 4.1 Fig. 4.1 (not drawn to scale) (a) Complete the ray diagram in Fig. 4.1 to indicate the actual path of the light rays from the line on the floor of the pool to the surface of the water. [2] (b) The refracted ray R makes an angle of 40 to the horizontal surface of the pool. Find the angle of incidence of the incident ray directed from the line on the floor of pool to the surface of the water. (refractive index of water = 1.33) angle of incidence = …………………[2] Image of line seen by eye light ray seen by the eye surface of water apparent depth 40 R A

6 ©BPGHS 2021 6091 / SEC 4 EXP PHY PRELIM / P2 [Turn over (c) A layer of oil of refractive index 1.46 is smeared on the surface of the water. Suggest with a reason how the apparent depth of the pool as seen by the eye will be different relative to the original level labelled A in Fig. 4.1. ...................................................................................................................................... ………........................................................................................................................... …………………………………………………………………………………………………. …………………………………………………………