NYGH 2015-S3EOY-Physics P2

Class Register Number Name 南洋女子中学校 NANYANG GIRLS’ HIGH SCHOOL End-of-Year Examination 2015 Secondary Three PHYSICS 1 hour 45 minutes Paper 2 Theory Paper 09:15 – 11:00 Friday 09 October 2015 No additional materials are required. READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write your name, register number and class in the spaces at the top of this page and on any separate answer paper used. Write in dark blue or black ink. You may use a pencil for any diagrams or graphs. Do not use correction fluid or tape. Section A (40 marks) Answer all questions. Write your answers in the spaces provided on the question paper. Section B (30 marks) Answer all questions. Question 11 has a choice of parts to answer: 11 Either or 11 Or. Write your answers in the spaces provided on the question paper. At the end of the examination, circle 11 Either or 11 Or in the grid on the right to indicate which question you have answered. INFORMATION FOR CANDIDATES The intended number of marks is given in the brackets [ ] at the end of each question or part question. You are advised to spend no longer than one hour on Section A and no longer than 45 minutes on Section B. Candidates are reminded that all quantitative answers should include appropriate units. 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 use of an approved scientific calculator is expected, where appropriate. The gravitational field strength g is 10 N kg -1 (near the Earth’s surface). Examiner’s Use Paper 2 1 2 3 4 5 6 7 8 9 10 11 Either 11 Or Total Paper 1 Overall % Setters: AWL & AJL This document consists of 17 printed pages. NANYANG GIRLS’ HIGH SCHOOL [Turn over

2015 End-of-Year Examination Secondary Three 2 Nanyang Girls’ High School Setters: AWL & AJL Physics II Section A (40 marks) Answer all questions. Write your answers in the spaces provided. 1 Mrs Tan went to buy some durians. She noticed the seller weighed each durian individually and added the masses of the durians together to obtain the total mass. Fig. 1.1 (a) The scale shown in Fig. 1.1 was used to weigh a durian. Record the mass of the durian that is shown on the scale to the correct precision in kg. mass of durian = ……………………………. [ 1] (b) Mrs Tan bought 4 durians. When she weighed them altogether at home, the scale showed a mass that was 100 g less than what she was charged for . State if Mrs Tan’s method of weighing the durians will give a more accurate mass than the seller’s method. Explain the reasoning behind your answer. Assume that both scales have the same precision and accuracy. …………………………………………………………………………………………..… ………………………………………………………………………………………. …. … …………………….……………………………………………………………. ………… ……………………………………………………………………………………. …… [3]

2015 End-of-Year Examination Secondary Three 3 Nanyang Girls’ High School Setters: AWL & AJL Physics II [Turn over 2 In a journey along a straight road, a car accelerates uniformly from rest to 46.4 m s−1 in 10.0 s. It then travels at this constant speed for 500 m before decelerating uniformly to rest in 20.0 s. (a) Calculate the acceleration of this car in the first 10.0 s. acceleration = ………….………[2] (b) Determine the time taken by the car to travel the 500 m in the middle o f the journey. time taken = ………….………[2] (c) Using the axes below, s ketch and label a graph to show how the speed of the car varies with time during the entire journey. Indicate the speed and time clearly for each stage of the journey. [2]

2015 End-of-Year Examination Secondary Three 4 Nanyang Girls’ High School Setters: AWL & AJL Physics II 3 Fig. 3.1 shows three blocks lying on a smooth horizontal surface. The blocks A, B and C have mass of 4.0 kg, 3 .0 kg and 2.0 kg respectively. A pushing force P is exerted on block A as shown. Fig. 3.1 (a) Calculate the horizontal force P needed to accelerate the blocks at 2.1 m s −2. F = ………….………[1 ] (b) Determine the force exerted on A by B. force = ………….………[ 2] (c) Determine the net force on C. net force = ………….………[1] A B C P

2015 End-of-Year Examination Secondary Three 5 Nanyang Girls’ High School Setters: AWL & AJL Physics II [Turn over 4 A force F is applied horizontally on a 26 kg box to keep it at rest on a frictionless inclined plane as shown in Fig. 4.1. Fig. 4.1 (a) On Fig. 4.1, draw and label two other forces acting on the box. [1] (b) Hence, sketch a vector diagram (not to scale) to show the vector addition of all the forces acting on the box to keep it at rest. Clearly label the forces and angles. [3] (c) Without the addition of other forces, s uggest how you may modify the way the force F is applied to keep the box at rest on the plane, such that F has a smaller magnitude. …..………………………………………………………….………………………………. …..…………………………………………………………………….………………... [1]

2015 End-of-Year Examination Secondary Three 6 Nanyang Girls’ High School Setters: AWL & AJL Physics II 5 (a) State the principle of moments. …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………….……………………[1] Fig. 5.1 shows a baby mobile that hangs by a string from the ceiling. Objects P, Q, R and S hang from 3 rods. The toy is completely stationary and the rods are horizontal. The weights of the strings and the rods may be neglected. Fig. 5.1 (b) Calculate length y. length y = …………………… [2] (c) Determine the mass of R and S. mass of R = ……………………; m ass of S = ………………….… [2] l l 3.0 cm y x x mass = 180 g mass = 70 g Q P R S rod 1 rod 2 rod 3

2015 End-of-Year Examination Secondary Three 7 Nanyang Girls’ High School Setters: AWL & AJL Physics II [Turn over (d) If object R drops off, state what will happen to rod 1 and rod 3. rod 1: ………………………………………………….. ……………………. …………… ……………………………………………………………………………………………[1] rod 3: …………………………………………………..…………………….…………… ……………………………………………………………………………………………[1] 6 A bubble of gas rises 40.0 m from a diver to the surface of a lake, as shown in Fig. 6.1. Fig. 6.1 (a) If atmospheric pressure is 101 kPa and the density of the lake water is 1000 kg m-3, calculate the air pressure inside the bubble at the depth of 40.0 m in pascal. air pressure =……………………….[3] 40.0 m gas bubble surface of lake

2015 End-of-Year Examination Secondary Three 8 Nanyang Girls’ High School Setters: AWL & AJL Physics II (b) State and explain how the volume of the bubble will change as it rises to the surface of the lake. ……………………………………………………………………………………………… ……………………………………………………………………………………………… …………………………………………………………………………………………. [2] 7 A car of mass 1800 kg is trave lling along a straight, level road at a constant speed of 70 km h -1. (a) Calculate the kinetic energy of the car. kinetic energy of car = ……………………. [2] (b) A total frictional force of 400 N is acting on the car. Determine the work done against this force in 1 minute. work done = ……………………. [2] (c) Hence, determine the power of the car engine required to do work against friction. power of engine = ……………………. [ 1]

2015 End-of-Year Examination Secondary Three 9 Nanyang Girls’ High School Setters: AWL & AJL Physics II [Turn over 8 A letter ‘F’ is placed in front of a plane mirror as shown in Fig. 8.1