SCGS 2022 Prelim P2

1 SINGAPORE CHINESE GIRLS’ SCHOOL PRELIMINARY EXAMINATION 2022 SECONDARY FOUR CANDIDATE NAME CLASS 4 REGISTER NUMBER CENTRE NUMBER INDEX NUMBER PHYSICS 6091/2 Monday 29 August 2022 1 hour 45 mins Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST 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 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. Take g = 10 ms-2 or 10 Nkg-1 unless stated otherwise. This question paper consists of 26 printed pages. For Examiner’s Use Section A 50 Section B 30 Total 80

2 SECTION A Answer all the questions in this section. 1 Fig. 1.1 shows two engineers measuring the length of a wall made from concrete. Fig. 1.1 (not to scale) The wall is 2.0 m high, 15.0 m long and 0.25 m thick. The mass of the wall is 18 000 kg. (a) The engineers measure the length of the wall in one single measurement. State the name of the measuring instrument they use. ……………………………………………………………….. [1] (b) The engineers state that the density of the concrete affects the pressure exerted by the wall on the ground but that the length of the wall does not affect this pressure. (i) Calculate the average density of the concrete. Average density = ……………….. [2] (ii) Calculate the average pressure exerted by the wall on the ground. Average pressure = …………….. [2]

3 (iii) Without further calculation, explain why doubling the length of the wall does not change the pressure that the wall exerts on the ground. ………………………………………………………………….………………………. ………………………………………………………………………………………….. ………………………………………………………………………………………...... [1] [ Total : 6 m ]

4 2 Fig. 2.1 shows