NJC_2025_H2_Physics_Prelim_P2_QP

[Turn over NATIONAL JUNIOR COLLEGE SENIOR HIGH 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME SUBJECT CLASS REGISTRATION NUMBER PHYSICS Paper 2 Structured Questions Candidate answers on the Question Paper. 9749/02 2 Sep 2025 2 hours No Additional Materials are required. READ THE INSTRUCTION FIRST Write your subject class, registration number and name in the spaces at the top of this page. Write in dark blue or black pen on both sides of the paper. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Answers all questions. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 / 8 2 / 10 3 / 6 4 / 6 5 / 10 6 / 10 7 / 10 8 / 20 Total / 80 H

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3 [Turn over

4 Answer all the questions in the spaces provided. 1 A small pellet of mass 8.00 × 10–3 kg is projected at an angle 𝜃 above the horizontal, as shown in Fig.1.1. The speed of projection is u. The pellet reaches a maximum height of 10.0 m and travels at a speed of 5.00 m s–1 at maximum height. (a) Air resistance is negligible. (i) Using energy conservation, show that the initial speed of projection is 14.9 m s–1. [1] (ii) Calculate the angle of projection 𝜃. 𝜃 = …………….……. ° [2] (iii) Determine the time taken by the pellet from launch to impact with the ground. 10.0 m Ground Fig. 1.1 q

5 [Turn over time = …………………. s [2] (iv) Determine the average rate of change of momentum of the pellet from the instant of projection to the instant before it hits the ground. rate of change of momentum = ……………… N [1] (b) Fig. 1.2. shows part of the graph (up to the maximum height) of the variation with time of the vertical displacement of the pellet when air resistance is not negligible. Complete the graph from the maximum height to the instant the pellet hits the ground. Numerical values are not required. [2] [Total: 8] 0 Vertical displacement time Fig. 1.2

6 2 (a) Momentum is conserved when two objects collide. State the condition under which momentum is conserved. ……………………………………………………………………………………………………………… …………………………………………………………………………………………………………….[1] (b) Fig. 2.1 shows the variation with time of the momentum of two colliding trucks A and B. Fig. 2.1 The masses of trucks A and B are 2000 kg and 4000 kg respectively. The period of collision is between 1.5 s and 3.0 s. (i) Calculate the force acting on truck B during the coll