Pei Hwa 2022 Pure Phy Paper 2 MS

2022 4E Physics Prelim – ANSWERS PAPER 1 1. A 2. A 3. A 4. A 5. D 6. C 7. D 8. B 9. B 10. C 11. B 12. B 13. C 14. C 15. B 16. C 17. B 18. C 19. B 20. B 21. B 22. C 23. A 24. C 25. D 26. B 27. A 28. B 29. C 30. D 31. D 32. B 33. C 34. B 35. C 36. C 37. B 38. B 39. C 40. C PAPER 2 1 (a) A to B: moving upwards with constant acceleration B to C: moving downwards with constant acceleration C to D: coming to a stop after being in contact with the ground Generally okay. Some students did not use the correct phrases. However, marks were awarded as long as description was correct. Some students mixed up the first two phrases. [1] 2 correct [2] all correct (b) 2.79 m Generally okay. Some students did not read the graph properly. Mark was given as long as the reading taken was only maximum one square away. [1] (c) 5.29 m Generally okay. Some students did not read the graph properly. Mark was given as long as the reading taken was only maximum one square away. [1] (d) Badly done. Students made the following mistakes: - Did not know how the shape would be like - Did not see that the distance travelled from 0 – 0.5 s = distance travelled from 0.5 – 1.0 s [1] for curve [1] for horizontal part ecf 2 (a) height above B = 1.5cos20 GPE at A = KE at B m(10)(1.5 – 1.5cos20) = (1/2)mv2 v = 1.35 m/s [1] [1],[1] [1]

2 Badly done. Students made the following mistakes - Did not understand that the concept asked was initial GPE = final KE - Did not find the change in height, but may have found horizontal or diagonal distances (b) decreasing acceleration Very badly done. Mark given if student indicated an increase in speed, for leniency. [1] (c) T = 2.4334 (2.4334)(7) + 2.4334/4 = 17.6 s [1] for substitution [1] Badly done. Students should visualise the entire movement of the pendulum to find out the number of periods. 3 (a) When a body is in equilibrium, the sum of clockwise moments about a pivot is equal to the sum of anticlockwise moments about the same pivot. Generally okay. All students are encouraged to get all definition questions correct. [1] (b) (12)(6) + (8)(10) = R(7) + (10)(10) R = 7.43 N Generally okay. Students who got this wrong mainly mixed up the directions. [1],[1] [1] (c) There is a resultant clockwise moment about the pivot. The object will rotate clockwise before coming to rest, with the center of gravity below the pivot. [1] [1] Badly done. Mistakes made: - Students were not clear enough in indicating when the object would come to a stop. - Students missed out that weight would be a factor and produce a moment, thus thinking object would remain stationary. 4 (a) Reduce heat loss through conduction and convection As vacuum has no particles / no medium Not well done. Few students indicated both pro