Beatty Prelim J 4E5N 5086 Phy P2 2025 final for review (1)

BEATTY SECONDARY SCHOOL PRELIMINARY EXAMINATION 2025 SECONDARY FOUR EXPRESS / FIVE NORMAL (ACADEMIC) / G3 CANDIDATE NAME CLASS REGISTER NUMBER SCIENCE (PHYSICS, CHEMISTRY) 5086/02 Paper 2 Physics 29 August 2025 Setter: Mrs Seah 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and register number on all the work you hand in. You may use an HB pencil for any diagrams, graphs, tables or rough working. Write in dark blue or black pen. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. Section A Answer all questions. Write your answers in the spaces provided on the question paper. Section B Answer only one question. Write your answers in the spaces provided on the question paper. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use A 55 B….. 10 Total 65 This document consists of 21 printed pages and 1 blank page. [Turn over

2 Section A Answer all the questions in the spaces provided. 1 (a) A student compares microwaves and ultraviolet radiation in a vacuum. Complete the sentences with only the phrases provided higher than less than the same as The frequency of ultraviolet radiation is higher than the frequency of microwaves. [1] The speed of microwaves in a vacuum is the same as the speed of ultraviolet radiation in a vacuum. [1] (b) State the region of the electromagnetic spectrum that is used for sun-tanning beds. Ultraviolet radiation [1] 2 Fig. 2.1 shows how the speed of a vehicle changes with time. Fig. 2.1 (a) Describe the motion of the vehicle from t = 200 s to t = 220 s. Uniform/constant deceleration ……………………………………………………………………………………….. [1] (b) Calculate (i) the acceleration of the vehicle in the first 70 s. 𝒂 = 𝒗−𝒖 𝒕 = 𝟐𝟓.𝟎 𝟗𝟎 𝒐𝒓 ( 𝟏𝟗.𝟓 𝟕𝟎 ) = 0.278 or = 𝟎. 𝟐𝟕𝟗 = 0.28 m / s2 (2sf or 3sf) acceleration = ………………… m/s2 [1] 30 25 20 15 10 5 0 20 40 60 80 100 120 140 160 180 200 220 speed m/s time / s

3 (ii) the distance travelled for the whole journey. Total distance = area under graph = 𝟏 𝟐 [(𝟏𝟗𝟎 − 𝟗𝟎) + 𝟐𝟐𝟎) × 𝟐𝟓. 𝟎 = 4000 m distance travelled = ……………… m [2] 3 A cylindrical beaker with a base area of 30.0 cm 2 contains a mixture of two immiscible liquids, A and B. The mass of the beaker is 50.00 g. The beaker is placed on an electronic beam balance as shown in Fig. 3.1. Fig. 3.1 (a) Calculate the average density of the mixture. volume = 13 x 30.0 = 390 cm3 average density = (460 – 50) / 390 = 1.05 g / cm3 average density = ………………. g / m3 [2] (b) The density of liquid A is known to be 1.00 g/cm3. Calculate the density of liquid B. mass of A = density of A x volume of A = 1.00 x (3 x 30.0) = 90.0 g density of B = mass of B / volume of B = (410 – 90.0) / (390 – 90.0) = 1.07 g / cm3 density = ………………. g /cm3 [2] liquid A liquid B 3.0 cm 460.00 g electronic beam balance inner base 10.0 cm

4 (c) Calculate the pressure exerted on the inner base of the beaker due to the mixture. Inner base area = 30/(100 x 100) = 0.003 m2 or 3 x 10-3 m2 pressure = weight acting on inner base / cross-sectional area = (( 𝟒𝟏𝟎 𝟏𝟎𝟎𝟎)𝐱𝟏𝟎)÷(0.003) = 1370 Pa pressure = ……………….. Pa [3] 4 Fig. 4.1 shows a ball of mass 0.50 kg sliding down a rough slope from position A which is 7.5 m above the ground with an initial speed of v m/s. Friction along the slope produces 10.7 J of thermal energy. The initial speed v m/s decreases as the ball rolls down the slope to position B. The ball leaves the slope at position B moving vertically upward and reaches a height of 13.0 m above the ground at position C. (a) Explain why the speed of the ball decreases as it travels from position A to position B with the relevant energy transfers between the different energy stores. From point A to before point B, the energy in the ball is transferred from the gravitational potential store and kinetic store to the internal store (of surrounding air and ball). Work is done against friction or to overcome friction along the slope and the speed of the ball decreases as thermal energy is dissipated to surroundings. From point A to before point B, the energy transferred is by heating from the gravitational potential store and kinetic store of ball to the internal store (of surrounding air and ball). …………………………………………………….…………………………………... [3] Fig. 4.1 13.0 m 7.5 m B A C v m/s

5 (b) Calculate the (i) gravitational potential store of the ball at position C, GPE = mgh = 0.50 x 10 x 13 = 65 J gravitational potential store = ……………….. J [1] (ii) initial speed v, at position A. Assuming there is no energy loss, GPE at C + WD against friction = total energy at A (GPE + KE) 65 + 10.7 = ( 𝟏 𝟐 x 0.50 x v2) + (0.50 x 10 x 7.5) v = 12.4 m/s initial speed = ……………….. m/s [2] 5 A solid substance at 30.0 oC is heated for 20 min until it melts at 150 oC. It takes 10 min for the substance to melt completely. Fig. 5.1 (a) Sketch on Fig. 5.1 the variation in temperature of the substance with time until it melts completely. [2]

6 (b) State and explain what happens to the average energy in the kinetic store of the molecules as the substance is cooled until room temperature. The average kinetic energy decreases. Energy in the internal store (kinetic energy) of the substance is transferred to the internal store of the surroundings by the propagation of infrared waves. …………………………………………………….…………………………………... [2] 6 Fig. 6.1 shows a metal pipe being used as a simple heat exchanger by a student in an investigation. Heat is transferred from the hot water inside the metal pipe to the cold water outside the metal pipe in the basin. Fig. 6.1 Name and describe the process in which all the cold water in the basin is heated. Convection The heated water expands, becomes less dense and rises. The surrounding water being denser, sinks to be heated. The movement of water due to a difference in density sets up convection currents. …………….…………………………………………….…………………………………… [3] basin cooler water out hot water in thermometer cold water metal pipe

7 7 An instrument produces sound waves in air. The pressure of the sound wave is measured as shown in Fig. 7.1. Fig. 7.1 The speed of sound in air is 320 m/s. Calculate the wavelength of the sound wave produced. f = 1 𝑇 = 1 2𝑥10−3 =500 Hz v = f  = 320 500 = 0.64 m = 64 cm (allow e.c.f) wavelength = ……………….. cm [2] 1 2 3 4 5 6 7 pressure / Pa + 0.1 + 0.2 - 0.1 - 0.2 time / ms 0

8 8 Fig. 8.1 shows a rectangular tank containing a ball floating in water at position X. A ray of light from the ball strikes the plane mirror at the bottom of the tank, making an angle of 22.2° with the normal at the water surface. The ray will be reflected from the surface of the mirror and emerge at a point on the surface of the water. Fig. 8.1 (a) On Fig. 8.1, draw the