GESS 4Exp Phy Prelim P2 24

This paper consists of 22 pages including the cover page GAN ENG SENG SCHOOL Preliminary Examination 2024 CANDIDATE NAME CLASS INDEX NUMBER PHYSICS Paper 2 Sec 4 Express 6091/02 28 August 2024 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. 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. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions. Write your answers in the spaces provided. Section B Answer one question. Write your answers in the spaces provided. 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, as more marks are awarded for sound use of Physics than for correct answers. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Section A 70 Section B 10

GESS 4EXP PHY P2 Prelim 24 TYL (CHL) 2 Section A [70 marks] Answer all the questions in this section. 1 In a car race called “demolition derby”, collisions between cars are common. Fig. 1.1 is a graph showing the motion of a car during the race. Fig. 1.1 (a) Estimate the displacement of the car at 500 s. displacement = ………………………… [2] (b) Estimate the average speed of the car from 0 s to 500 s. average speed = ………………………… [2] [Total: 4] time / s velocity / km h-1

GESS 4EXP PHY P2 Prelim 24 TYL (CHL) 3 2 A rock of weight 20 N is thrown through the air. At a particular time, a force of 50 N acts on the rock at an angle of 45  to the vertical, as shown in Fig. 2.1. Fig. 2.1 (not to scale) (a) Draw and label, with the letter R, the resultant force acting on the rock where a length of 1.0 cm represents 5.0 N. Determine the direction of the resultant force. resultant force = ………………………… [2] direction …………………………….…………………………………………………. [1]

GESS 4EXP PHY P2 Prelim 24 TYL (CHL) 4 (b) When the rock reached the highest point at a height of 15.0 m above the ground, it momentarily stopped and then dropped down vertically. If air resistance is negligible, calculate the speed of the rock just before it hit the ground. speed = ………………………… [2] [Total: 5] 3 The device shown in Fig. 3.1 is used to covert old newspapers into blocks that can be burnt. Fig. 3.1 (not to scale) The newspapers are soaked in water. The soaked paper is packed into the container. When a force F is applied at the end of the handle, the plate squeezes the water out of the paper and leaves a block. The area of the plate in contact with the paper is 0.025 m2. The perpendicular distance from the pivot to the rod holding the plate is 10.0 cm. A force F is applied normal to the handle at a distance 30.0 cm from the pivot. A pressure of 7.2 kPa is needed to squeeze the water out of the paper. (a) State what is meant by pressure of 7.2 kPa. ……………………………………………………………………………………………… ………………………………………………………………………………………….. [1]

GESS 4EXP PHY P2 Prelim 24 TYL (CHL) 5 (b) Calculate (i) the force that is exerted by the rod to cause a pressure of 7.2 kPa on the paper, force = ………………………… [2] (ii) the force F applied at the end of the handle to exert a pressure of 7.2 kPa on the paper. force F = ………………………… [2] [Total: 5] 4 Fig. 4.1 shows a hand dryer. Fig. 4.1 The hot air that blows out of the dryer causes evaporation of water from the hands. (a) Explain why the water on the hands evaporates rather than boils. ……………………………………………………………………………………………... …………………………………………………………………………………………. [1]

GESS 4EXP PHY P2 Prelim 24 TYL (CHL) 6 (b) Describe, using the kinetic particle model of matter, what happens to the water on the hands as it evaporates. …………………………………………………………………………………………….... …………………………………………………………………………………………….... …………………………………………………………………………………………….... ………………………………………………………………………………………….. [2] (c) State the main electromagnetic wave that transfers heat to the hand. ………………………………………………………………………………………….. [1] (d) State one difference and one similarity between this electromagnetic wave and sound produced by the dryer. Difference …………………………………………………………………………………. ………………………………………………………………………………………….. [1] Similarity …………………………………………………………………………………... ………………………………………………………………………………………….. [1] (e) Singapore aims to achieve “net zero emissions by 2050”. Suggest and explain the renewable source of energy used to operate the dryer in Singapore. …………………………………………………………………………………………….... …………………………………………………………………………………………….... …………………………………………………………………………………………….... ………………………………………………………………………………………….. [2] [Total: 8]

GESS 4EXP PHY P2 Prelim 24 TYL (CHL) 7 5 Four identical bulbs are labelled ‘1.5 V, 0.50 A’ which describes the conditions for them to operate at normal brightness. A 12 V battery is connected to the bulbs as shown in Fig. 5.1. Fig. 5.1 (a) State and explain if light from the bulbs is a transverse or longitudinal wave. ……………………………………………………………………………………………... …………………………………………………………………………………………. [1] (b) State one difference between red light and green light. ……………………………………………………………………………………………... …………………………………………………………………………………………. [1] (c) Calculate the resistance of R if the bulbs are to operate at normal brightness. R = ………………………… [3] (d) State how and explain why the bulbs are arranged as shown in Fig. 5.1. ……………………………………………………………………………………………... ……………………………………………………………………………………………... …………………………………………………………………………………………. [2] [Total: 7] R 12 V

GESS 4EXP PHY P2 Prelim 24 TYL (CHL) 8 6 An electric heater, labelled 230 V, 270 W, is placed near the surface of some water in a beaker. Two temperature se nsors A and B are placed in the water. Sensor A is near the surface of the water and sensor B is at the bottom of the beaker, as shown in Fig. 6.1. Fig. 6.1 Fig. 6.2 shows how the temperature recorded by each sensor changes with time. Fig. 6.2 (a) Explain why the temperature recorded by sensor B changes very little. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. …………………………………………………………………………………………… [2] temperature / C  7  6  5  4  3  2  1 time / min  0

GESS 4EXP PHY P2 Prelim 24 TYL (CHL) 9 (b) Suggest and explain where the heater should be placed so that both sensors record approximately the same temperature. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. ……………………………………………………………………………………………….. …………………………………………………………………………………………… [2] (c) The specific heat capacity of water is 4 200 J kg -1 C-1. Using the readings of sensor A from Fig. 6.2, calculate the mass of water in the beaker at 6 minutes. State one assumption you have made in your calculation. Assumption ………………………………………………………………………………... ………………………………………………………………………………………….... [1] mass = ………………………… [2] (d) Determine the current in the heater. current = ………………………… [2] [Total: 9]

GESS 4EXP PHY P2 Prelim 24 TYL (CHL) 10 7 (a) State what is meant by an electric field. ……………………………………………………………………………………………... …………………………………………………………………………………………. [1] (b) Some students were asked to dr