NBSS 4E Science Physics Prelim P2 v3

NAVAL BASE SECONDARY SCHOOL PRELIMINARY EXAMINATION, 2026 O Name: _________________________ ( ) 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, graphs, tables or rough working. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions. 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 rather than for correct answers. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Section A 55 Section B 10 Total 65 Parent’s/Guardian’s Signature SCIENCE (PHYSICS)Chang Setter: Ms Janessa Chang Candidates answer on the Question Paper. No Additional Materials are required. 5086/02 24 August 2026 1 hour 15 min This document consists of 18 printed pages and 2 blank pages. Class: ________________

2 Section A Answer all questions in this section. 1 Fig. 1.1 shows how the speed of a car varies with time. The car is initially travelling at constant speed. Fig. 1.1 At time t = 0 s, the driver sees an obstacle on the road 50 m in front of the car. He then steps on the brake pedal to bring the car to a stop. From time = 0 s till rest, the car travels in a straight path. (a) Explain why the speed only decreases after some time. …………………………………………………….…………………………….. …………………………………………………….………………………….[1 ] speed / m/s time / s 0 0 5 10 15 20 25 30 0.5 1.0 1.5 2.0 2.5 3.0

3 [Turn Over (b) Determine, with appropriate calculations, if the car collided with the obstacle. …………………………………………………….…………………………….. …………………………………………………….………………………….[2 ] (c) Calculate the deceleration of the car from 0.6 s to 2.8 s. deceleration = ........................ m/s2 [2] (d) The driver and car have a total mass of 1600 kg. Calculate the braking force acting on the car while it is decelerating. braking force = ........................ N [2] [Total: 7]

4 2 Fig. 2.1 shows a toy drone hovering in the air at constant height above the ground. Fig. 2.1 The mass of the drone is 5.5 kg. You may take gravitational field strength to be 10 N/kg. (a) Calculate the magnitude of the upward force. upward force = ........................ N [1] (b) The upward force is now increased to 80 N. Calculate the acceleration of the drone. acceleration = ........................ m/s2 [2] (c) The toy drone suddenly malfunctions and the upward force no longer acts. The toy drone falls and eventually reaches a constant speed. Explain, in terms of forces, why it reaches a constant speed. …………………………………………………….…………………………….. …………………………………………………….…………………………….. …………………………………………………….…………………………….. …………………………………………………….………………………….[2 ] [Total: 5]

5 [Turn Over 3 Fig. 3.1 shows the side view of an empty 4- wheel cart of weight 100 N. A downward force of 150 N is applied to the handle of the cart so that the two front wheels X just lift off the ground as shown. Fig. 3.1 The centre of gravity C of the cart is a horizontal distance d from the pivot P. (a) Calculate the contact force on each back wheel Y just as the front wheels X are lifted off the ground. contact force on each back wheel Y = ........................ N [2] (b) Calculate distance d. d = ........................ m [3] [Total: 5] 150 N C X floor pivot P 20 cm Y d

6 4 Fig. 4.1 shows a skier of mass 75 kg skiing down a very steep, frictionless slope. The skier starts from rest at the top A of the slope. His weight causes him to accelerate down the slope. When the skier reaches the bottom B of the slope, the energy in his kinetic store is 5.5 ×104 J. The gravitational field strength is 10 N/kg. (a) Calculate the vertical height between A and B. height = ........................ m [2] Fig. 4.1 27 m skier A B C

7 [Turn Over At B, the skier digs his skis into the snow and took 4.5 s to stop at the point C after travelling 27 m horizontally. (b) Determine the average horizontal force that acts on the skier between B and C. force = ........................ N [2] (c) Determine the rate of energy transfer by the skier between B and C. rate of energy transfer = ........................ W [2] [Total: 6]

8 5 Fig. 5.1 shows the cooling curve of liquid P. Fig. 5.1 (a) State, for each region, whether the energy in the internal store of the liquid increases, decreases or remains constant. region energy in the internal store AB BC CD DE [2] (b) State the process occurring during region BC and explain the shape of the graph in the region. …………………………………………………….…………………………….. …………………………………………………….…………………………….. …………………………………………………….…………………………….. …………………………………………………….…………………………….. …………………………………………………….…………………………….. …………………………………………………….…………………………….. …………………………………………………….………………………….[3 ] temperature / °C time / min B C D E A

9 [Turn Over (c) Explain why temperature remains constant at DE. …………………………………………………….…………………………….. …………………………………………………….………………………….[1 ] [Total: 6] 6 Fig. 6.1 shows the positions of air particles at an instant in time, t, when a sound wave, travelling from left to right, passes through air. At the time, t, shown, the air particles X and Y are at their original undisturbed positions. Fig. 6.1 Fig. 6.2 (a) (i) On Fig. 6.1, mark the centre of compression of the wave with the letter C and the centre of rarefaction with the letter R. [1] (ii) On Fig. 6 .2, sketch the variation of pressure with distance at time t. [1] X Y time t atmospheric pressure distance pressure

10 (b) The pitch of the sound wave is decreased. Explain whether the speed and wavelength of the sound wave will change. …………………………………………………….…………………………….. …………………………………………………….…………………………….. …………………………………………………….………………………….[2 ] [Total: 4] 7 An electrical circuit is set up as shown in Fig. 7.1. The voltmeter reads 5.0 V. Fig. 7.1 (a) Calculate the effective resistance of the 3.0 Ω and 6.0 Ω resistors. effective resistance = ........................ Ω [2] V A resistor Q 12 V 3.0 Ω 6.0 Ω 2.0 Ω