2025 TKGS Pure Physics Prelim P2

Tanjong Katong Girls’ School 2 Sec 4 Preliminary Examination 2025 Section A Answer all questions in this section. 1 Fig 1.1 shows an arrow about to be released. When the bowstrings are stretched to the extent shown in Fig. 1.1, the tension in each of the bowstrings is 80 N, while the angle between the bowstring and arrow is 45°. Draw a scaled vector diagram to determine the magnitude of the resultant force acting on the arrow due to the bowstrings just before it is released. scale = .............................................. magnitude of resultant force = ..............................................[4] [Total: 4] 2025 Phy Set 7

Tanjong Katong Girls’ School 3 Sec 4 Preliminary Examination 2025 2 Fig. 2.1 shows a child sliding down a slope on a snow sledge. Fig 2.1 At time t = 0, the child and the sledge begin to move down the hill. When the child sees a wall ahead, he applies the brake and eventually comes to a stop. Fig. 2.2 shows the velocity time graph of the journey. Fig 2.2

Tanjong Katong Girls’ School 4 Sec 4 Preliminary Examination 2025 (a) Explain, using ideas of forces, why the speed varies in the way shown in Fig 2.2 between t = 0 s and t = 26 s. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………[3] (b) Explain how the graph shows that the child and the sledge reach terminal velocity. ………………………………………………………………………………………………… ………………………………………………………………………………………………[1] (c) At t = 26 s, the front of the sledge is 35 m away from the wall. Determine if the child is able to come to a stop before hitting the wall. ………………………………………………………………………………………………… ………………………………………………………………………………………………[2] (d) State the main energy changes during time t = 24 s to t = 26 s. ………………………………………………………………………………………………… ………………………………………………………………………………………………[1] (e) At t = 26 s, when the brakes are first applied, the child jerks forward on the sledge. Explain why this happens. ………………………………………………………………………………………………… ………………………………………………………………………………………………[1] [Total: 8]

Tanjong Katong Girls’ School 5 Sec 4 Preliminary Examination 2025 3 Fig 3.1 shows a crane with a boom angle of 30° used on construction sites to lift heavy loads. The length of the crane boom is 45.0 m and the perpendicular distance of the load to the pivot X is 22.0 m. Fig 3.1 Table 3.1 shows the maximum load the crane can support at different boom angles. boom angle / ο maximum load / N 30 11 500 45 14 000 60 20 000 Table 3.1 . (a) Explain why the