DHS 2019 JC1 MYE Physics

Name: Index Number: Class: DUNMAN HIGH SCHOOL Mid Year Examination Year 5 H2 PHYSICS Multiple Choice and Structured Questions Additional Materials: Multiple Choice Answer Sheet 9749 9 July 2019 2 hours READ THESE INSTRUCTIONS FIRST Write your class, index number and name on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Section A There are fifteen questions in this section. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Section B Answer all questions. 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. For Examiner’s Use Section A MCQ 15 Section B 1 10 2 10 3 16 4 10 5 5 6 9 s.f. -1 Total 75 This document consists of 20 printed pages and 0 blank page.

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4 Section A Answer all the questions. You are advised not to spend more than 30 minutes on Section A. 1. Which estimate is realistic? A The mean kinetic energy of a typical saloon car traveling on an expressway in Singapore is 300 kJ. B The density of a tennis ball is 30 g cm−3. C The power of a hair dryer is 10 kW. D The pressure of air in a car tyre is 2 ×103 Pa. 2. Students A, B, C and D, each made a series of measurements of the acceleration of free fall, g. The table shows the results obtained. Which student obtained a set of results that could be described as precise but not accurate? Student Results, g / m s−2 A 9.79 9.83 9.84 9.81 B 8.46 8.45 8.41 8.50 C 8.76 9.45 9.21 8.99 D 9.81 10.12 8.94 9.89 3 An aeroplane travels at an average speed of 600 km h−1 on an outward flight and at 400 km h−1 on the return flight over the same distance. What is the average speed of the whole flight? A 111 m s−1 B 167 m s−1 C 480 km h−1 D 500 km h−1

5 4 A man standing at the top of a building releases a stone from rest. One second later, he throws a marble vertically downward with an initial velocity. Which of the following graphs best represents the velocity-time graphs for the stone (S) and the marble (M)? Ignore the effects of air resistance. 5 Two masses make an elastic collision. What are their speeds after the collision? 2.0 kg mass 6.0 kg mass A 2.0 m s−1 4.0 m s−1 B 4.0 m s−1 6.0 m s−1 C 5.0 m s−1 3.0 m s−1 D 7.0 m s−1 1.0 m s−1 5.0 m s−1 3.0 m s−1 2.0 kg 6.0 kg

6 6 A man is standing on a weighing scale in a lift. Which of the following statements is always true? A When the lift is moving down, the reading on the weighing scale is greater than the weight of the man. B When the lift is moving up, the reading on the weighing scale is greater than the weight of the man. C The weight of the man is equal in magnitude and opposite in direction to the normal contact force acting on him due to Newton’s third law of motion. D The weight of the man is equal in magnitude to the force that he exerts on Earth. 7 A hinged door is held closed in the horizontal position by a cable. Three forces act on the door: the weight W of the door, the tension T in the cable, and the force H at the hinge. Which list gives the three forces in increasing order of magnitude? A H,T,W B T,H,W C W,H,T D W,T,H

7 8 A bore hole of depth 2000 m contains both oil and water as shown. The pressure at the bottom is 17.5 MPa. The density of the oil and water are 830 kg m–3 and 1000 kg m–3 respectively. What is the depth x of the oil? A 907 m B 1000 m C 1090 m D 1270 m 9 A bungee jumper has 24 kJ of gravitational potential energy at the top of his jump. He is attached to an elastic rope which starts to stretch after a short time of free fall. The values of gravitational potential energy, elastic potential energy and kinetic energy are given for the top and the bottom of the jump. gravitational potential energy / kJ elastic potential energy / kJ kinetic energy / kJ top bottom 24 0 0 24 0 0 Which row of the table below shows possible values of these three energies when the jumper is half-way down? Losses of energy through air resistance are negligible. gravitational potential energy / kJ elastic potential energy / kJ kinetic energy / kJ A B C D 12 12 8 12 2 8 8 10 10 4 8 2

8 10 A driving force of 200 N is needed for a car of mass 800 kg to travel along a level road at a speed of 20 m s−1. What power is required to maintain the car at this speed up a gradient in which the car rises 1 m for each 8 m travel along the road? A 6.0 kW B 7.2 kW C 20 kW D 24 kW 11 In an amusement park, a horizontal metal beam of length 20 m is spun about its midpoint while park-goers of various masses are seated in identical light harnesses at varying distances from the midpoint as shown. At a steady angular velocity, the park-goers will be tilted at fixed angles from the vertical. (not to scale) Which of the following correctly describes the angles? A 123 4θθθθ= = = B 234θθθ>> C 23 12 , θθ θθ= > D 41 4 sinθθ= 5 m 5 m 5 m 5 m mass m mass m mass 3m mass 4m θ1 θ2 θ3 θ4

9 12 The diagram shows a child sitting on a playground turntable, which is turning with constant angular velocity. Which diagram shows the forces acting on the child when in the position shown? A B C D support force from platform weight friction support force from platform centripetal force friction weight support force from platform friction centripetal force weight friction support force from platform centripetal force weight

10 13 Three uniform masses are in a row, with their centres along a straight line as shown. What is the distance, x, in metres, if the net force acting on the 1 kg mass is zero? A 4.6 B 6.0 C 7.5 D 9.0 14 A small mass is initially at a distance d from the centre of a planet, where d is greater than the radius of the planet. It takes work W to move the mass from distance d to a distance 2d from the centre of the planet. What is the work required to move it from 2d to 3d? A W 6 B W 3 C 3 W D 6 W 15 A communication satellite which takes 24 hours to complete one orbit is replaced by a new satellite which has twice the mass of the first. If the new satellite also has an orbit of 24 hours, what is the value of the ratio radius of orbit of new satellite radius of orbit of old satellite A 1 : 2 B 1 : 1 C 2 : 1 D 2 : 1 x 15 m 9 kg 1 kg 4 kg