2024 Serangoon SS Sci(Phy) Prelim P2 Section B

SERANGOON SECONDARY SCHOOL PRELIMINARY EXAMINATION SECONDARY 4 EXPRESS CANDIDATE NAME ( ) CLASS CENTRE NUMBER S INDEX NUMBER SCIENCE PHYSICS 5086/02 Paper 2 (Section B) 26 Aug 2024 1 hour 15 minutes Candidates answer on the Question Paper. Setter(s): READ THESE INSTRUCTIONS FIRST Write your Centre number, 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 staplers, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. Section B Answer one question. Write your answers in the spaces provided on the question paper. The number of marks is given in brackets [ ] at the end of each question or part question. This question paper consists of 7 printed pages, including this cover page. For examiner’s use Section B Total 10

2 Section B [10 marks] Answer one question from this section. 12 Fig. 12.1 shows a space rocket bring launched at sea level. The space rocket has a main engine and boosters that help the shuttle to lift off from the Earth. For the rocket to escape Earth’s gravitational field, it has to reach its breaking speed. Fig. 12.1 The combined mass of the space rocket remains constant at 22 500 kg throughout the launch. It accelerates uniformly over a distance of 825 km before it reaches its breaking speed of 10 km/s. (a) (i) On Fig. 12.2, sketch a speed-time graph of the rocket from launch to reaching its breaking speed. Label all relevant values on your graph. [2] Fig. 12.2

3 (ii) Determine the time taken for the rocket to reach its breaking speed. time taken = ………………………… [2] (iii) Determine the acceleration of the rocket. acceleration = ………………………… [2] (iv) Assuming no air resistance, calculate the upward thrust of the rocket. The gravitational field strength g is 10 N/kg. upward thrust = ………………………… [2]

4 (b) In reality during launch, the space rocket will burn solid fuel that is inside the fuel compartment until it reaches its breaking speed to escape Earth’s gravitational field. Once the compartment is empty, it will be detached from the main body. The main engine will be cut off as the rocket continues to travel through outer space with no air resistance. Explain how this affects the acceleration and the speed of the rocket. …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… ……………………………………………………………………………………. [2] [Total: 10]

5 13 Fig. 13.1 shows an electric kettle labelled “240 V, 1200 W”.