[5086/02] SAS(S) 2024 4E5N Prelims QP

Preliminary Examination 2024/Sec 4E / Sci(PHY) 2 __________________________________________________________________________________ Section A [55 marks] Answer all the questions in this section. Answer in the spaces provided. 1 A car with a mass of 2500 kg completes a journey with the speed-time graph shown below. (a) Describe the motion of the car during the entire journey. ………………………………………………………………………………………….….. ……………………………………………………………………………………….…….. …………………………………….………………………………………….…...…..…[2] (b) Calculate the deceleration of the car. deceleration = …………………………m/s2 [2] (c) Determine the resistive force acting on the car. resistive force = ………………………N [2] time / s speed/ m/s

Preliminary Examination 2024/Sec 4E / Sci(PHY) 3 __________________________________________________________________________________ [Turn over (d) Explain, in terms of forces, why speed of the car decreases from t = 15 s to t = 25 s. ………………………………………………………………………………………….….. ……………………………………………………………………………………….…….. …………………………………….………………………………………….…...……[2] 2 A toy car, initially at rest, rolls down a smooth slope as shown in Fig. 2.1. Fig. 2.1 The height of the slope is 1.2 m. The mass of the car is 600 g. The gravitational field strength is 10 N/kg. (a) Calculate the gravitational potential energy of the car. gravitational potential energy = ………………. J [2] (b) Calculate the speed of the car when it hits the bottom of the slope. speed = ……………. m/s [2] smooth slope rough level road 1.2 m

Preliminary Examination 2024/Sec 4E / Sci(PHY) 4 __________________________________________________________________________________ (c) If the friction along the level road is 3 N, calculate the distance moved by the car before it stops. distance = ……………. m [1]

Preliminary Examination 2024/Sec 4E / Sci(PHY) 5 __________________________________________________________________________________ [Turn over 3 Fig. 3.1 shows a uniform metre rule of weight 10 N pivoted at end X. A block of weight 3 N is hung 30 cm from the pivot, while a spring balance is suspended at the 80 cm mark from the pivot and the rule is balanced. Fig. 3.1 (a) State what is meant by the principle of moments. ………………………………………………………………………….…………………….….. ……………………………………………………………………………………….…….…….. …………………………………….………………………………………………..…...……[2] (b) (i) On Fig. 3.1, draw an arrow to represent the weight of the metre rule. Label it as W. [1] (ii) Hence, calculate the moment due to the weight of the metre rule about the pivot at end X. moments = ………………………Ncm [2] (c) Calculate the upward force measured by the spring balance about the pivot at end X. upward force = …………………….N [2]

Preliminary Examination 2024/Sec 4E / Sci(PHY) 6 __________________________________________________________________________________ 4 A sphere of material X, weighing 3.5 N, is shown in Fig 4.1. Fig 4.1 The gravitational field strength is 10 N/kg. (a) Calculate the mass of the sphere. mass = ………………………kg [2] (b) The volume of a sphere is measured by dropping it into a container of oil, as shown in Fig 4.2. Fig 4.2 Determine the volume of the sphere. volume = ……………... cm3 [1] oil sphere

Preliminary Examination 2024/Sec 4E / Sci(PHY) 7 __________________________________________________________________________________ [Turn over (c) Use your answers in parts (a) and (b) to calculate the density of material X. density = ……………... g/cm3 [2]

Preliminary Examination 2024/Sec 4E / Sci(PHY) 8 __________________________________________________________________________________ 5 Fig. 5.1 shows a kettle containing water placed on the burner of a gas cooker. Fig 5.1 The gas burner is lit at time t = 0. At t = 250 s the temperature of the water is 100 °C, the boiling point of water. (a) State what is meant by boiling point. ………………………………………………………………………………………………. ……………………………………………………………………………………………[1] (b) Fig. 5.2 shows how the temperature of the water changes with time t. Fig 5.2 (i) Thermal energy (heat) is transferred to the water at a constant rate but the temperature of the water increases at a rate that is not constant, as shown in Fig. 5.2. Explain why the temperature increases in this way. ................................................................................................................................ .............................................................................................................................[1] t/s temperature/oC

Preliminary Examination 2024/Sec 4E / Sci(PHY) 9 __________________________________________________________________________________ [Turn over (ii) When the temperature reaches 100 °C, the kettle is left on the burner. Thermal energy is still supplied to the water. The water boils as the molecules form bubbles and rise to the surface. Explain, in terms of the molecules, why it is necessary to supply thermal energy in order to keep the water boiling. .......................................................................................................................................... .......................................................................................................................................... ...........................................................................................................................[2]

Preliminary Examination 2024/Sec 4E / Sci(PHY) 10 __________________________________________________________________________________ 6 Fig. 6.1 shows the path of a ray of light as it enters a rectangular glass block at P. The light ray is refracted at P. (a) Calculate the refractive index of the glass block. refractive index = ………………………[2] (b) Given that the speed of light in the air is 3.0 x 10 8 m/s, find the speed of light in the glass block. speed = ……………………… m/s [2] Fig. 6.1 P 40° 60°

Preliminary Examination 2024/Sec 4E / Sci(PHY) 11 __________________________________________________________________________________ [Turn over 7 Fig 7.1 shows a girl standing a few hundred metres away from a large building. Fig 7.1 The girl uses a signal generator and a loudspeaker to send a short pulse of sound towards the building. The sound has a frequency of 3700 Hz. A short time later, the girl hears an echo. (a) State the two quantities to be measured so as to determine the speed of the echo. ………...……………………………………………………………………….…………