2024 SJI Y4OP Prelim P2 detailed ans

ST. JOSEPH’S INSTITUTION PRELIMINARY EXAMINATION 2024 (YEAR 4) CANDIDATE NAME MARK SCHEME CLASS INDEX NUMBER PHYSICS Paper 2 Candidates answer on the Question Paper. No Additional Materials are required. 6091/02 9 September 2024 1 hour 45 minutes (08:05 – 09:50) READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Write in dark blue or black pen. You may use an 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. Section A Section B 1 2 3 4 5 / 6 / 8 / 5 / 8 / 8 6 7 8 9 - / 5 / 10 / 10 / 10 - 10 11 / 10 / 10 This document consists of 41 printed pages and 1 blank page. For examiner’s use Section A 70 Section B 10 Total 80

2 Section A Answer all questions. 1 A car is speeding along a straight road that has a speed limit of 50 km/h. The car passes a policeman on a stationary motorcycle at t = 0. The policeman starts chasing the car, using his motorcycle, at t = 0.50 s. Fig. 1.1 shows the velocity-time graph of the car. Fig. 1.1 (a) Using information from Fig.1.1, show that the car has exceeded the speed limit. 50 km/h = 14 m/s Or 24 m/s = 86.4 km/h Since speed > 50 km/h therefore car is speeding 0 5 10 15 20 25 30 35 car time /s velocity m/s 1.0 2.0 3.0 4.0 5.0 6.0 7.0

3 (b) The velocity of the policeman’s motorcycle increases uniformly from rest at t = 0.50 s at a rate of 6.0 m/s2. (i) On Fig 1.1,  draw the velocity-time graph of the policeman’s motorcycle from t = 0 until t = 6.0 s  indicate the velocity of the motorcycle at t = 6.0 s. Show all relevant working. a=v−ut v=u+at =0+(6.0)(5.5) =33.3 m/s straight line from 0 m/s to 33 m/s from t = 0.50 s to t = 6.0 s

4 (ii) At t = 7.5 s, the car notices the motorcycle and starts decelerating uniformly from 24 m/s to rest. The motorcycle also decelerates uniformly, and at t = 10.5 s, both come to a complete stop. Calculate the distance between them at t = 10.5 s. Distance travelled by car between t = 0s and 10.5s = ½ (10.5 + 7.5)×24 = 216 m Velocity of motorcycle at t = 7.5: a = (v – u)/t 6.0 = (v – 0)/(