Bowen Prelim P2

1 [Turn over Class Full Name Index Number Preliminary Examination 2024 I believe, therefore I am PHYSICS Secondary 4 Express Paper 2 Structured and Free Response 22 August 2024 1 hour 45 minutes Candidates answer on Question Paper. No additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name and index number 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. Indicate your choice in the table provided below. For Examiner’s Use Section A Section B Total 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. O 6091/02 70 10 80 This document consists of 24 printed pages, including the cover page.

2 [Turn over Section A Answer all questions. 1 (a) Define velocity. …………………………………………………………………………………….. [1] (b) A 7.5 kg rock is thrown vertically upwards from the surface of a planet. The rock leaves the surface of the planet with a speed of 4.0 m s–1 at time t = 0. Fig. 1.1 shows the velocity-against time graph of the rock. Fig. 1.1 Assume that the planet does not have an atmosphere and that the resistive force acting on the rock is negligible. (i) Using the graph, determine the weight of the rock on the planet. weight = …………………. [3] For Examiner’s Use

3 [Turn over (ii) Calculate the maximum height the rock reached before it starts falling. maximum height = …………………… [1] (iii) The same rock was thrown vertically upwards on Earth with a speed of 4.0 m s -1. Assuming resistive forces are also negligible on Earth and acceleration due to gravity is 10 m/s2, draw the velocity against time graph of the rock and label it E on Fig. 1.1. [2] [Total: 7] For Examiner’s Use 2 A very deep tank is used when training sailors to escape from submarines. The tank is cylindrical and open to the air at the top. Fig. 2.1 shows the tank. Fig. 2.1 (not to scale) The area of the base of the tank is 4.2 x 105 cm2 and the tank is filled with water to a depth of 35 m. (a) The density of water is 1000 kg / m3. Calculate the pressure, due to the water, on the base of the tank. pressure = ........................... [1] 35 m

4 [Turn over (b) The pressure in the water at the base of the tank is 450 kPa. (i) Explain why the pressure in the water at the base of the tank differs from the value calculated in (a). .................................................................................................................. ............................................................................................................ [1] (ii) Calculate the force exerted on the base of the tank. force = ............................ [1] (c) Force is a vector quantity and pressure is a scalar quantity. State how a vector quantity differs from a scalar quantity. .......................................................................................................................... ..................................................................................................................... [1] For Examiner’s Use

5 [Turn over (d) Fig. 2.2 shows the equipment that is used to measure the pressure of the gas in a flask at sea level. Fig. 2.2 The atmospheric pressure is 1.0 × 105 Pa at sea level. The distance between mercury level P and mercury level Q is 320 mm. The density of mercury is 13600 kg / m3. Determine the pressure of the gas inside the flask in mm Hg. pressure = …………………… mm Hg [2] [Total: 6] For Examiner’s Use

6 [Turn over 3 The boiling point of nitrogen is –196 °C. Liquid nitrogen, below its boiling point, is stored in a vacuum flask, as shown in Fig. 3.1. Fig. 3.1 The flask has two glass walls with a vacuum between them. (a) State where, in the apparatus shown in Fig. 3.1, evaporation occurs. …………………………………………………………………………………….. [1] (b) Other than the location where evaporation occurs, describe two other differences between evaporation and boiling. ……………………………………………………………………………………….. ……………………………………………………………………………………….. ……………………………………………………………………………………….. ……………………………………………………………………………………. [2] (c) State and explain the advantage of having a vacuum between the two glass walls. ……………………………………………………………………………………….. ……………………………………………………………………………………….. ……………………………………………………………………………………….. …………………………………………………………………………………….. [2] For Examiner’s Use

7 [Turn over (d) The liquid nitrogen reaches –196 °C, its boiling point. A small piece of metal at 20 °C is lowered slowly into the liquid nitrogen. The small piece of metal has a mass of 50 g. When it is lowered into the liquid nitrogen, the metal cools to –196 °C. The specific heat capacity of the metal is 390 kJ / (kg K). The specific latent heat of vaporisation of nitrogen is 200 J / g. Calculate (i) the thermal energy lost from the metal as it cools, thermal energy = ……………………. [2] (ii) the mass of nitrogen that boils away. mass = …………………… [1] [Total: 8] 4 Fig. 4.1 gives the names of the five components of the electromagnetic spectrum arranged by decreasing frequency. Fig. 4.1 (a) State the component in Fig. 4.1 which is not in the correct position. ……………………………………………………………………………………. [1] X-rays Microwaves Ultra-violet Infra-red Radiowaves For Examiner’s Use

8 [Turn over (b) State which of the five components [2] (i) has smallest wavelength, ………………………………………………… (ii) is used for home Wi-Fi signal, …………………………………………… (iii) is used in a television remote control. ………………………………….. (c) Explain why ultrasound is not a component of the electromagnetic spectrum. ………………………………………………………………………………………... ……………………………………………………………………………………. [1] (d) Ultrasound and X-rays are used in hospitals to produce images of regions in the human body. Both procedures need a source of waves and a detector. Fig. 4.2 Fig. 4.3 Draw and label the positions of the source and the detector (i) on Fig. 4.2, when ultrasound produces an image of region P, [1] (ii) on Fig. 4.3, when X-rays produce an image of region Q. [1] [Total: 6] For Examiner’s Use

9 [Turn over 5 (a) A student rubs a plastic ruler against a piece cloth made of wool. The student tests the ruler and finds it is positively charged. Explain how the ruler becomes positively charged. ............................................................................................................................ .........................................