PHS 2024 4Exp PP Prelim P2 (Shared)

1 [Turn over Name:....................................... Register/Index Number: ............... Class: .............. PRESBYTERIAN HIGH SCHOOL PHYSICS 6091/2 Paper 2 22 August 2024 Thursday 1 hour 45 minutes PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL PRESBYTERIAN HIGH SCHOOL 2024 SECONDARY FOUR EXPRESS PRELIMINARY EXAMINATION INSTRUCTIONS TO CANDIDATES DO NOT OPEN THIS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO Write your class, register number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glues or correction fluid. Section A Answer all questions in the spaces provided. Section B Answer one question in this section. The number of marks is given in brackets [ ] at the end of each question or part question. 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. This document consists of 28 printed pages. For Examiner’s Use Section A Section B Total

2 [Turn over Section A Answer all the questions in the spaces provided. 1 Fig. 1.1 shows a cricket ball as it comes into contact with a cricket bat. The cricket ball has a mass of 0.16 kg and it hits the bat with a speed of 25 m/s. After being in contact with the bat for 0.013 s, the ball rebounds with a speed of 22 m/s in the direction exactly opposite to its original direction. (a) State one difference between speed and velocity. ……………………………………………………………………………………………… ……………………………………………………………………………………………… ………………………………………………………………………………………….. [1] (b) Calculate the acceleration experienced by the cricket ball when it is struck by the bat. acceleration = ……………… [2] Fig. 1.1

3 [Turn over (c) Hence, determine the resultant force exerted on the ball by the bat. resultant force = ……………… [1]

4 [Turn over 2 Fig. 2.1 shows a uniform rectangular concrete slab that is 4.0 m in length, 3.0 m in width and 0.10 m in thickness. It rests on a brick wall and is the roof of a bus shelter. The density of the concrete slab is 1750 kg/m3. (a) The gravitational field strength, g is 10 N/kg. Calculate the weight of the rectangular concrete slab. weight = ……………… [2] 4.0 m Fig. 2.1 concrete slab cables

5 [Turn over (b) Using principle of moments, determine the total downward force exerted by the cables on the slab. total downward force = ……………… [2] (c) Hence, determine the upward force exerted by the brick wall on the concrete slab. upward force = ……………… [2]

6 [Turn over 3 Fig. 3.1 shows a skier of mass 85 kg skiing down a very steep smooth slope. The gravitational field strength, g is 10 N/kg. The skier starts moving from the top T of the slope with an initial speed of 2 m/s. The force of gravity accelerates him down the slope. When he reaches the bottom B of the slope, his speed is 30 m/s. (a) (i) Calculate the difference in height between T and B. difference in height = ……………… [2] Fig. 3.1 (not to scale) skier

7 [Turn over (ii) State one assumption you have made regarding the energy transfer for your calculation in (a) (i). ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………. [1] (b) At B, the skier digs his skis into the snow and stops at the point P after travelling 33 m horizontally. Calculate the average braking force that acts on the skier between B and P. average braking force = ……………… [2]

8 [Turn over Fig. 4.1 (not scale) 4 A student uses a pump to inflate a bicycle tyre. Fig. 4.1 shows the pump and the tyre. (a) The pressure of the trapped air in the pump is 3.8 × 105 Pa and the cross-sectional area of the piston is 6.1 cm2. (i) Calculate the force exerted on the piston by the trapped air in the pump. force = ……………… [2] (ii) The student pushes the handle to the right and the piston forces the trapped air into the tyre. The force exerted by the student is less than the value in (a)(i). Suggest one reason why. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………. [1] tyre tyre trapped air pump piston handle valve

9 [Turn over (b) Under the hot sun, the temperature of the trapped air in the pump increases. Explain, in terms of its molecules, why the student needs to use a larger force to push the handle of the pump. ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ………………………………………………………………………………………….. [2]

10 [Turn over 5 A wave travels along a rope from left to right. Two points on the rope , A and B , have vertical displacement dA and dB respectively. The variation of d A and dB over the same time interval t is shown in Fig. 5.1. (a) State the amplitude of the wave. amplitude = ……………… [1] (b) Point B is 38 cm to the right of point A. (i) There are several possible values for the speed of the wave on the rope. Show that one possible value for the speed of the wave is about 200 cm/s. Show your working clearly. [2] (ii) Explain why there are other possible values for the speed of the wave. ……………………………………………………………………………………… ……………………………………………………………………………………. [1] point A point B Fig. 5.1 dA / cm 2.0 1.0 −2.0 −1.0 dB / cm 2.0 1.0 −2.0 −1.0 t /s t /s