2024 CHS Sec 4 Physics Prelim Paper 2

Name: Index Number: Class: CATHOLIC HIGH SCHOOL Preliminary Examination Secondary 4 (O-Level Programme) PHYSICS 6091/02 Paper 2 Structured and Free Response 23 August 2024 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, index number and class on all the work you hand in. Write in dark blue or black link. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, 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 only: Section A / 70 Section B / 10 Total / 80 Overall Marks % Paper 1 40 30% Paper 2A 70 50% Paper 2B 10 Paper 3 40 20% This document consists of 23 printed pages. 70  s.f.  formula Paper 2A

2 Section A Answer all the questions in this section. 1 A ball is thrown vertically upwards from ground level. Air resistance is not negligible. The variation with time t of the velocity v of the ball is shown in Fig. 1.1. Fig. 1.1

3 (a) (i) Describe the motion of the ball from t = 0 s to t = 1.75 s. [2] (ii) Explain, in terms of forces acting, why the ball moves as described in (a)(i). [3] (b) State the time where the gradient of the graph is equal to the magnitude of the acceleration of free fall. time = [1] (c) The ball falls back to ground level at t = 3. 50 s without reaching terminal velocity. Sketch, on Fig. 1.1, the variation of the velocity of the ball with time from t = 1.75 s to t = 3.50 s. [2]

4 2 Fig. 2.1 shows an electric motor and pulley wheel being used to raise a load M. The electric motor uses a belt to turn the pulley wheel. Fig. 2.1 (a) When the electric motor lifts the load, it transfers energy. Describe the energy transfers between the electric motor, the load M and the surrounding air. Assume there are no energy transfers to the belt and pulley wheel. [3]

5 (b) Fig. 2.2 shows the force on the pulley from the load M. Fig. 2.2 The weight of load M is 2.5 N and the weight acts at a distance of 20 cm from the pivot of the pulley wheel. Calculate the moment of the weight of load M about the pivot.