NJC 2021 SH1 Promo P1 (final)

[Turn over NATIONAL JUNIOR COLLEGE SENIOR HIGH 1 PROMOTIONAL EXAMINATION Higher 2 CANDIDATE NAME SUBJECT CLASS REGISTRATION NUMBER PHYSICS Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet 9749/01 29 September 2021 1 hour READ THE INSTRUCTION FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, subject class and registration number on the Answer Sheet in the spaces provided unless this has been done for you. There are thirty questions on this paper. 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 Optical Mark Sheet. Read the instructions very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. The use of an approved scientific calculator is expected, where appropriate. This document consists of 14 printed pages and 2 blank pages. OAS index number is in 5-digit format. 5 digit format: 2nd digit and the last four digits of the Reg Number. e.g. 0905648 = 95648.

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4 1 The table shows the abbreviations for multiples and sub -multiples and their corresponding powers of ten. Which power of ten is not stated correctly? A pico 10–12 B nano 10–9 C mega 106 D tera 109 2 A voltmeter connected across a resistor in a circuit gives readings which have high precision but low accuracy. Which of the following best describes the likely error in readings taken with this voltmeter? random error systematic error A high high B high low C low high D low low 3 In the diagram, x and y are two vectors. PS = PQ and ST = PR. What does vector z represent? A x + y B x – y C –x – y D y – x 4 An elevator is moving downwards with an acceleration of 5.8 m s–2. A ball, held 2.0 m above the floor of the elevator and at rest with respect to the elevator, is released. How long does it take for the ball to reach the floor of the elevator? A 0.51 s B 0.64 s C 0.83 s D 1.00 s Q P S R T x y z

[Turn over 5 5 Two cars X and Y are initially travelling at 30 m s–1 on a straight motorway. X overtakes Y by accelerating for 5.0 s to 35 m s –1, remaining at 35 m s –1 for a time T and then decelerating for 5.0 s to 30 m s–1. X advances by 100 m relative to Y during overtaking. The diagram shows the velocity-time graph for X. What is time T ? A 10 s B 15 s C 20 s D 25 s 6 In a tennis match, a ball is hit horizontally with a speed v, as shown in the diagram. The bottom of the ball is initially 3.0 m above the ground and a horizontal distance of 12 m from the net. The ball just clears the net, which is 1.0 m high. What is the value of v ? (Neglect the effects of air resistance.) A 16 m s–1 B 19 m s–1 C 30 m s–1 D 38 m s–1

6 7 A body of mass 2 kg is traveling at a velocity of 15 m s–1 at time t = 0. A force F acts in the direction of motion. The variation of the force F with time t is shown in the graph below. What is the velocity of the body at t = 100 ms? A 17 m s–1 B 19 m s–1 C 2000 m s–1 D 4000 m s–1 8 Two identical spheres, each of mass m and traveling with speed v, are moving towards each other. The two spheres have a head-on elastic collision. Which statement is correct? A The sum of the momenta before the impact is 2mv. B The total kinetic energy before the impact is zero. C The total kinetic energy after the impact is mv2. D The spheres stick and move together after impact. 9 A toy car can be launched from its launcher remotely. The mass of the car is m while the launcher’s mass is 4m. The toy is placed stationary on a smooth surface as shown. The toy car is launched with an initial kinetic energy of K. What is the kinetic energy of the launcher immediate after the toy car is launched? A 1 5 K B 1 4 K C 1 16 K D 1 25 K F /N 80 60 40 20 0 50 100 150 200 t /ms m m v v launcher toy car

[Turn over 7 10 A General-Purpose Machine Gun shoots bullets at a rate of 750 rounds per minute. Each bullet weighs 5.6 g and its average velocity in its effective range is taken to be 840 m s–1. What is the force experienced by a target board, if the all the bullet is assumed to hit the target and embedded in the board? A 35 N B 59 N C 3.5 kN D 59 kN 11 A small crane is used to load a crate weighing 600 N onto a barge. The man uses a rope and applies a force of 300 N to the rope. What is the tension in the cable from the crane? A 690 N B 600 N C 520 N D 300 N 12 A hinged shelf is held horizontally against a wall by a cable PQ. The forces acting on the shelf are its weight, the force exerted by the cable and the force exerted by the hinge H. Which arrow could represent the direction of the force the hinge exerts on the wall?

8 13 A lump of ice floats in water as shown. Which statement correctly explains why it floats? A The lump of ice floats because the area of its surface is larger than the area of its upper surface. B The pressure acting upwards on the lower surface of the ice is always larger than the pressure acting downwards on its upper surface. C The mass of water displaced is equal to the upthrust. D The pressure difference between the lower and upper surfaces of the lump of ice gives rise to an upthrust equal in magnitude to its weight. 14 A steel ball is released at rest from the surface of oil in a tall cylinder so that it falls to the bottom of the cylinder. Which graph shows the variation with time of the gravitational potential energy, EP and the kinetic energy EK of the ball? A B C D

[Turn over 9 15 In a hydroelectric power station, water is supplied from a reservoir 80 m above the power station. The water passes through its turbines at a rate of 6.0 m3 s–1. Assume the density of water is 1000 kg m–3. If the efficiency of the power station is 60%, what is the electrical power output? A 4.7 MW B 2.8 MW C 1.9 MW D 0.29 MW 16 A car of mass 1100 kg is travelling at a constant speed of 15 m s–1 up a slope inclined at 10o to the horizontal. The combined frictional forces acting on the car are directed down the slope and are equal to 5 W , where W is the weight of the car. What is the useful output power of the car’s engine? A 190 kW B 60 kW C 32 kW D 28 kW 17 An object travels at constant speed around a circle of radius 1.0 m in 1.0 s. What is the magnitude of its acceleration? A zero B 1.0 m s–2 C 2π m s–2 D 4π2 m s–2 18 A toy car travels along a track which contains a vertical circular loop of radius 0.10 m as shown. What is the minimum speed of the car required at the top of the circular loop to prevent it from falling off the track? A 10 m s–1 B 1.4 m s–1 C 1.0 m s–1 D 0.30 m s–1 0.10 m

10 19 A small object of mass 0.10 kg is released from rest at the rim of a semi -spherical bowl of radius 20 cm. Take g = 10 m s–2. The normal reaction force on the object when it passes the bottom of the bowl is A 3.0 N B 2.5 N C 2.0 N D 1.0 N 20 Values of the acceleration a of a particle moving in simple harmonic motion as a function of its displacement x are given in the table below. a / mm s–2 16 8 0 –8 –16 x / mm –4 –2 0 2 4 The period of the motion is A 1 𝜋 s B 2 𝜋 s C 2 s D π s 21 A small mass executes simple harmonic motion about a point P with amplitude a and period T. Its displacement from P at time T 8 after passing through P is A 𝑎 8 B 𝑎 √2 C 𝑎 2√2 D 𝑎 2 22 The diagram shows the graph of displacement against time for a body performing simple harmonic motion. At which point are t