CEDAR 2025 PHY PRELIM P2 QP

1 CEDAR GIRLS’ SECONDARY SCHOOL PRELIMINARY EXAMINATION 2025 SECONDARY FOUR CANDIDATE NAME CLASS INDEX NUMBER PHYSICS 6091/02 Paper 2 Structured and Free Response 28 August 2025 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and index number. Write in dark blue or black pen. You may use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, 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 1 / 7 2 / 6 3 / 7 4 / 5 5 / 7 6 / 7 7 / 7 8 / 4 9 / 10 10 / 10 Section B 11 / 10 12 / 10 Deduction Total / 80 This document consists of 24 printed pages.

2 Section A Answer all the questions in this section. 1 The resistive forces that act backwards on a car are air resistance and friction, as shown in Fig. 1.1. Fig. 1.1 Fig. 1.2 shows a graph of total resistive force that acts on the car against time t. t / s Fig. 1.2 The car is at rest at t = 0. The forward driving force acting on the car is zero until t = 1.0 s. From t = 1.0 s until t = 12 s, the forward driving force has a constant value of 2400 N. (a) (i) State the two time intervals when the resultant force acting on the car is zero. .................................................................................................................................... [1] (ii) Describe the motion of the car during these two intervals. ......................................................................................................................................... …………………………………………………………………………………………………… ………………………………………………………………………………………………... [2] air resistance friction forward driving force 0 1 2 3 4 5 6 7 8 9 10 11 12 3000 2000 1000 0 total resistive force / N 0

3 (b) The car has a mass of 800 kg. (i) Calculate the acceleration of the car at t = 3.0 s. acceleration = …………….………….. [2] (ii) Calculate the value of t when the acceleration of the car is 0.50 m/s2. t = …………….………….. [2] [Total: 7]

4 2 Fig. 2.1 shows a barrier at the entrance to a car park. The wooden barrier arm has a weight of 60 N which acts through the centre of gravity at the position shown on Fig. 2.1. Fig. 2.1 (a) The wooden barrier arm is in equilibrium. The mass of the soft iron bar A is 23 kg. The gravitational field strength is 10 N/kg. Calculate d, the distance between the pivot and the joint holding the soft iron bar A. d = …………….………….. [2] (b) Fig. 2.2 shows a coil attached to a power supply placed below the soft iron bar A. Fig. 2.2 wooden barrier arm centre of gravity soft iron bar A joint pivot weight of wooden barrier arm = 60 N d 1.7 m weight = 60 N coil 1.7 m d pivot joint soft iron bar A power supply soft iron core

5 (i) State and explain what happens to the wooden barrier arm when the switch in the coil circuit is closed. …………........................................................................................................................... ……………....................................................................................................................... ......................................................................................................................................... ......................................................................................................................................... .................................................................................................................................... [2] (ii) A student suggests replacing the soft iron bar A with a steel bar of the same mass. Explain why a steel bar is less effective than a soft iron bar in the barrier. …………………………………………………………………………………………………… ……………………………………………….………………………………………………….. …………………………………………………………………………………………………… ………………………………………………………………………………………………... [2] [Total: 6]

6 3 At a sharp corner on a car racing circuit there is an escape lane as shown in Fig. 3.1. Fig. 3.1 The escape lane is a bed of small stones. The escape lane slopes upwards. A car of mass 700 kg approaches the escape lane at a speed of 40 m/s. The brakes fail and the car stops in the escape lane. (a) Show that the energy in kinetic store of the car is 560 kJ when it approaches the escape lane. [1] (b) Describe what happens to the energy in kinetic store of the car as it stops. ………………………………………………………………………………………………………….. ………………………………………………………………………………………………………….. ………………………………………………………………………………………………………….. ……………………………………………………………………………………………….…….... [2] (c) The car comes to rest 40 m along the escape lane, having risen through a vertical distance of 3.0 m. The gravitational field strength is 10 N/kg. Calculate (i) the change in energy in the gravitational potential store of the car when it stops in the escape lane, change in energy = …………….………….. [1] escape lane corner direction of racing car

7 (ii) the average frictional force exerted on the car in the escape lane. force = …………….………….. [2] (d) The frictional force exerted on the car in the escape lane is not constant. Suggest one factor, apart from the car’s speed, that affects the value of the frictional force. ………………………………………………………………………………………………………….. ………………………………………………………………………………………………………. [1] [Total: 7]

8 4 A small aircraft takes off from the horizontal deck of a ship. Before taking off, the aircraft is held in place by a holdback bar. When the holdback bar is released, the aircraft is pulled along the deck by a steam-powered piston as shown in Fig. 4.1. Fig. 4.1 (not to scale) The steam exerts a high pressure on the piston. (a) (i) Define pressure. …………………………………………………………………………………………………… ………………………………………………………………………………………………... [1] (ii) Explain, using ideas about particles, how the steam creates a pressure on the piston. ……………………………………………………………………………………...................... …………………………………………………………………………………………………… ……………………………………………………………………………………………….. [2] (b) When the pressure is high enough, the holdback bar is released. The steam pushes the piston along the pipe shown in Fig. 4.1. The piston has a cross-sectional area of 0.30 m2. The pressure of the steam in the tank is 2.1 × 10 6 Pa and a tmospheric pressure is 1.0 × 105 Pa. Determine the resultant force on the piston caused by the pressure difference. force = …………….………….. [2] [Total: 5] aircraft cable for piston to pull aircraft piston holdback bar tank containing steam and boiling water deck of ship pipe open to atmosphere

9 5 Fig. 5.1 shows a connection to the internet made from