SAJC Final Exam (H2) JC1 2025 timed trial

1 SAJC 2025 Final Exam Timed Trial/ 9478 [Turn Over Civic Group Index Number Name 25S ST. ANDREW’S JUNIOR COLLEGE JC 1 2025 Final Examination Time Trial PHYSICS, Higher 2 9478 19 September 2025 1 hours 20 minutes Candidates answer on the question paper. No additional materials are required. READ THESE INSTRUCTIONS FIRST Write your name, index number and Civics Group on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs or rough working. Do not use paper clips, highlighters, glue or correction fluid. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 / 7 2 / 11 3 / 10 4 / 13 5 / 13 Total / 54 Percentage / 100 Grade This question paper consists of 14 printed pages including this page.

2 SAJC 2025 Final Exam Timed Trial/ 9478 [Turn Over Data speed of light in free space c = 3.00 x 108 m s-1 permeability of free space o = 4  x 10-7 H m-1 permittivity of free space o = 8.85 x 10-12 F m-1 = (1/(36)) x 10-9 F m-1 elementary charge e = 1.60 x 10-19 C the Planck constant h = 6.63 x 10-34 J s unified atomic mass constant u = 1.66 x 10-27 kg rest mass of electron me = 9.11 x 10-31 kg rest mass of proton mp = 1.67 x 10-27 kg molar gas constant R = 8.31 J K-1 mol-1 the Avogadro constant NA = 6.02 x 1023 mol-1 the Boltzmann constant k = 1.38 x 10-23 J K-1 gravitational constant G = 6.67 x 10-11 N m2 kg-2 acceleration of free fall g = 9.81 m s-2 Formulae uniformly accelerated motion s = u t + ½ a t2 v2 = u2 + 2 a s work done on/by a gas W = p V hydrostatic pressure p =  g h gravitational potential  = r Gm− displacement of particle in s.h.m. x = xo sin  t velocity of particle in s.h.m. v = v0 cos  t v =   22 0 xx −

3 SAJC 2025 Final Exam Timed Trial/ 9478 [Turn Over Answer all the questions in the spaces provided. 1 A car starts from rest and t ravels upwards along a rough straight road inclined at 5.0 o to the horizontal, as shown in Fig. 1.1 below. The length of the road is 458 m and the car has a mass of 800 kg. The speed of the car increases to 28 m s-1 at the top of the cliff. The car then veers off the cliff and lands on flat ground below. Fig. 1.1 (a) Determine the height of the top of cliff from the ground. height = ……………………. m [1] (b) Calculate the time of flight for the car to leave the cliff to the point when it lands onto the ground. time = ……………………… s [2] 5.0o cliff car 28 m s-1 u ground

4 SAJC 2025 Final Exam Timed Trial/ 9478 [Turn Over (c) When the car lands, it loses 90% of its mechanical energy after its impact with the ground. It continues to move forward with a speed u. Determine this speed u. u = …………………… m s-1 [2] (d) The car then experiences a constant deceleration of 2.5 m s -2 while travelling on the ground. There is a wall that is at a distance of 100 m from the foot of the cliff as shown in Fig. 1.2 below . Given that the car lands 86 m from the foot of the cliff, determine if the car will collide with the wall. Fig. 1.2 ...………………………………………………………………………….……………………… …..……..…………………………………………………………………………………..….[2] 5.0o cliff car 28 m s-1 u ground wall 100 m not to scale

5 SAJC 2025 Final Exam Timed Trial/ 9478 [Turn Over 2 (a) Trolley A of mass 6.0 kg travelling at a speed of 5.0 m s−1 collides head-on with trolley B of mass 10 kg travelling at a speed of 3.0 m s−1 as shown in Fig. 2.1. Trolley B then travels backwards after the collision with a speed of 2.0 m s−1. (i) 1. Determine the speed of trolley A after the collision. speed = ………………………. m s −1 [2] 2. Explain whether the collision is an elastic or inelastic collision. Substantiate your conclusion with clear working. …………………………………………………………………….……………………..… ……..…………………………………………………………………………………….[2] Trolley A 6.0 kg Trolley B 10 kg 5.0 m s−1 3.0 m s −1 Fig. 2.1

6 SAJC 2025 Final Exam Timed Trial/ 9478 [Turn Over (ii) Fig. 2.2 shows how the velocity of trolley B vary with time. 1. Sketch the corresponding velocity-time graph for trolley A. [2] Fig. 2.2 2. Determine the force acting on trolley B. force = ………………………. N [2]

7 SAJC 2025 Final Exam Timed Trial/ 9478 [Turn Over (b) Fig. 2.3 shows a simplified cross -section diagram of a submarine, an aquatic vehicle whose buoyancy can be adjusted such that it can be allowed to sink underwater and float on the surface. This is achieved by flooding the rigid metal ballast tanks with seawater to an adjustable extent, thereby varying the volume o f air inside the ballast tanks. Fig. 2.3 (i) Explain how the variation of the volume of air and seawater in the ballast tanks can result in the submarine sinking or floating given the upthrust is constant when the submarine is fully submerged. ………….…………………………..……………………………………………………. ………….…………………………..…………………………………………………… …..…………………..………………………………………………...……..............[1] (ii) The submarine is cruising horizontally at 2.0 m s-1 when an underwater explosive mine is spotted. A 500 -kg torpedo is launched by the submarine horizontally to destroy the mine. The launching force on the torpedo over 500 ms launching period is shown in Fig. 2.4. Fig. 2.4 Determine the velocity of the torpedo after launch. velocity = ……..………… m s-1 [2] time / ms 0 force / kN 500 30

8 SAJC 2025 Final Exam Timed Trial/ 9478 [Turn Over 3 (a) State the conditions for a rigid body to be in equilibrium. ............................................................................................................................................ …........................................................................................................................................ ……................................................................................................................................ [2] (b) A uniform rigid rod of mass 30 kg is attached to a vertical wall by a hinge as shown in Fig. 3.1. The other end of the rod is held to the ceiling by a cable. Fig. 3.1 (i) Draw the free body diagram of the forces acting on the rod in Fig. 3.1. Label all the forces clearly. [2]

9 SAJC 2025 Final Exam Timed Trial/ 9478 [Turn Over (ii) Show that the tension T in the cable is 127 N. [2] (iii) Determine the force acting on the rod by the hinge. force = ………………………… N direction = ………………………………… [4]

10 SAJC 2025 Final Exam Timed Trial/ 9478 [Turn Over 4 (a) Define gravitational potential at a point in a gravitational field. …………..………………….…………………………………………………………………….. ………………………………….………………………………………………………………… ………………………………………………………………………………..……………..…[2] (b) Fig. 4.1 shows lines of equal gravitational potential near to the surface of a small spherical asteroid of mass M and radius R. (i) Explain why all the values of potential are negative. ………………….……………………………………………………………………..…… ………………….……………………………………………………………………..…… ………………….……………………………………………………………………..…… ………………….…………………………………………………………………….…[2] (ii) Write down the equation relating fiel