51 CGS 2013 P1 WorkedOutAns

_________________________________________________________________________ This paper consists of 16 printed pages, including the cover page. CRESCENT GIRLS’ SCHOOL SECONDARY FOUR PRELIMINARY EXAMINATION 5058/01 PHYSICS 28 August 2013 PAPER 1 1 hour Class: Register No: Name: READ THESE INSTRUCTIONS FIRST Write your name, index number and class in the spaces provided at the top of this page and on the optical answer sheet. Do not use staples, paper clips, highlighters, glue or correction fluid. There are forty questions in 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 optical answer sheet. Read the instructions in the Answer Sheet 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. Unless specified in the question, you may assume the following constants: Gravitational acceleration = 10 m/s2 Speed of light in vacuum = 3.0  108 m/s

2013 / CGS / 5058 / Prelim / P 1 2 1 A student ha s been asked to determine, as accurately as possible, the dimension s of a strand of optic fibre. The optic fibre is about 90 cm long and about 0.5 mm in diameter. Which measuring instruments should the student use? Length Diameter A Metre rule vernier calipers B Metre rule micrometer C Vernier calipers vernier calipers D Vernier calipers micrometer 2 A pair of vernier calipers is used to measure the thickness of a coin. With the jaws closed and no coin, the reading on the vernier calipers is shown in diagram 1. With the jaws closed around coin, the reading on the vernier calipers is shown in diagram 2. Diagram 1 Diagram 2 What are the zero error and the actual thickness of the coin? Zero error / cm Corrected reading / cm A – 0.02 4.05 B – 0.08 4.11 C 0.02 4.01 D 0.08 3.95 3 A strip of paper tape is pulled by a toy car under a vibrating arm. The arm vibrates regularly, making 50 dots per second. The average speed of the toy car is ___________. A 0.011 m/s B 1.1 m/s C 3.0 m/s D 300 m/s

2013 / CGS / 5058 / Prelim / P 1 3 4 A girl takes 6.0 s to walk from point W to point X, and takes 6.0 s to walk from point X to point Y, and finally takes another 6.0 s to walk from point Y to point Z as illustrated below. The points WXYZ forms a square with side 1 2 m. What is the magnitude of her average speed and velocity? Average speed (m/s) Average velocity (m/s) A 2.0 0.50 B 2.0 0.67 C 2.0 2.0 D 6.0 0.67 5 A boy who is standing at the bottom of a building throws a stone upwards to a man standing 2.0 m above the boy. If the stone is thrown up with a speed of 7.0 m/s, what is the speed of the stone at the instant when it is caught by the man? Assume that the air resistance and the height of the boy and man are negligible. A 3.0 m/s B 6.2 m/s C 9.0 m/s D 9.4 m/s 6 Three forces of magnitude 2 .0 N, 3 .0 N and 5 .0 N respectively act on an object of mass 4.0 kg. Which of the following cannot be the magnitude of the acceleration of the object? A 0 m/s2 B 1.0 m/s2 C 2.0 m/s2 D 3.0 m/s2 X Y Z 12 m W 12 m 12 m

2013 / CGS / 5058 / Prelim / P 1 4 7 Two blocks X and Y of weights 10 N and 6.0 N respectively are suspended by two strings. A downward force of 4.0 N is applied to Y. What are the tensions T1 and T2 in the two strings? T1 T2 A 8.0 N 10 N B 10 N 4.0 N C 14 N 6.0 N D 20 N 10 N 8 Which person in the following cases has the greatest inertia? A A 50 kg girl sprinting at 10 m/s B A 70 kg long–distance runner running at 5 m/s C A 90 kg man walking at 2 m/s D A 110 kg wrestler resting on a mat 9 The densities of metals X and Y are 7.6 g/cm3 and 3.0 g/cm3 respectively. Equal masses of X and Y are melted and mixed to form an alloy. What is the density of the alloy? A 1.25 g/cm3 B 2.15 g/cm3 C 4.30 g/cm3 D 5.30 g/cm3

2013 / CGS / 5058 / Prelim / P 1 5 10 The diagram shows a light rod with two weights hanging from it. A third weight is to be added to bring the system into equilibrium so that the rod is balanced. What weight is required and where should it be placed? Weight Position A 1.0 N 2.0 m to the left of the pivot B 1.0 N 3.0 m to the right of the pivot C 2.0 N 1.0 m to the left of the pivot D 2.0 N 1.0 m to the right of the pivot 11 The diagram shows four hollow pipes P, Q, R and S have one or two weights attached to their inner surfaces. Which hollow pipes are in the state of unstable equilibrium? A P and Q only B Q and R only C P, Q and R only D P, Q, R and S 12 The engine of a car of mass 500 kg generates power of 10000 W to move t he car. Find the time taken for the car to accelerate from a speed of 10 m/s to 20 m/s. A 2.5 s B 5.0 s C 7.5 s D 10 s P Q R S

2013 / CGS / 5058 / Prelim / P 1 6 13 A ball is dropped from the top of a building. Which graph best represents the relationship between the ball’s total energy and elapsed time as the ball falls to the ground? Assume air resistance is negligible. A B C D 14 The diagram shows a cylinder fitted with two pistons X and Y of diameters 5.0 cm and 10.0 cm respectively. The piston X is pushed by a force of 12 N. What is the force exerted on piston Y? A 3.0 N B 6.0 N C 24 N D 48 N Piston Y Piston X 12 N liquid

2013 / CGS / 5058 / Prelim / P 1 7 15 Diagram 1 shows an open–ended capillary tube in horizontal position with air trapped by a small, stationary mercury plug of 12 cm in length. Diagram 2 shows the same capillary tube in an upright position. The atmospheric pressure is 75 cmHg. Diagram 1 Diagram 2 What is the pressure of the trapped column of air in diagram 1 and 2? Diagram 1 Diagram 2 A 12 cmHg 75 cmHg B 12 cmHg 87 cmHg C 75 cmHg 63 cmHg D 75 cmHg 87 cmHg 16 The syringe in the diagram contains air at atmospheric pressure. The piston moves freely along the cylinder without any friction. When the syringe is heated from 40 C to 100 C, the piston moves outwards. When the temperature becomes steady, the piston stops moving. State how the value of each of quantities below compares at 100 C, after the piston stops, with its value at 40 C. Average speed of gas molecules Frequency of collisions between the gas molecules and the piston A Increases Increases B Increases Decreases C Increase No change D No change No change

2013 / CGS / 5058 / Prelim / P 1 8 17 When an object is being heated, which of the following statements is/are correct? I. Its temperature always increases. II. Its internal energy always increases. III. Its kinetic energy and potential energy cannot rise at the same time. A II only B I and II only C II and III only D All of the above 18 A faulty thermometer reads 10 °C and 90 °C when placed in