HYSS PLM_PHYSICS 6091 4G3 P2 [MS]

1 2024 Physics S4E PLM Hua Yi Secondary School HUA YI SECONDARY SCHOOL PRELIMINARY EXAMINATION 2024 SECONDARY 4E (PHYSICS) 6091 MARK SCHEME Q Answer Q Answer Q Answer Q Answer 1 D 11 A 21 D 31 B 2 B 12 A 22 B 32 B 3 C 13 D 23 D 33 A 4 C 14 C 24 B 34 C 5 C 15 D 25 C 35 A 6 D 16 A 26 A 36 A 7 B 17 C 27 D 37 A 8 A 18 A 28 C 38 D 9 A 19 A 29 A 39 D 10 C 20 D 30 A 40 D Section A [50 marks] Qn No. Answers Marks 1 (a) As the speed increases, the air resistance acting on the child and the sledge also increases. Hence the resultant force decreases and the acceleration decreases. From 24 to 26s, the forward force is equal to the backward force and the resultant force acting on the child and sledge is zero. Hence, there is no acceleration and it moves with a constant speed. Need to mention resultant force in each case to get the marks. B1 B1 (b) The gradient of the graph becomes zero/ graph become horizontal from t = 24 s to t =26 s. Need to state the time from t= 24s to 26s to get the mark. B1 (c) Distance travelled = Area under the graph = ½ x (30-26) x 15.2 = 30.4 m Since the sledge stops in 30.4 m, it will stop before hitting the wall which is 35 m ahead. M1 A1 (d) The energy in the gravitational potential store is transferred to energy in the internal store. OR Gravitational potential energy to thermal / internal energy Note: the speed is constant, there is no changes in energy in the kinetic store. Reject any answers that mention kinetic store. B1 (e) The child experience inertia where his body mass resists a change in state of motion / and continue to move forward. Inertia + resist a change in state of motion / continue to move forward B1 Total: [7]

2 2024 Physics S4E PLM Hua Yi Secondary School 2 (a) 6.0 s A1 (b) The rebound velocity of 30 m/s is lower/less than the initial velocity. OR The displacement traveled during rebound is less than the initial velocity. Accept distance instead of displacement. B1 (c) a = (v-u)/t a = (-40 – 40)/6 a = - 13.3 N/kg g = 13.3 N/kg Only accept positive gravitational field strength and unit m/s 2 is not acceptable. M1 A1 (d) The gradient / acceleration is constant so the ball did not reach terminal velocity / is free falling / experience no resistance. Need to have both. B1 Total: [5] 3 (a) As the boom angle increases, the perpendicular distance between the load and the pivot decreases. Since the moment is the product of the force and the perpendicular distance, a decrease in the perpendicular distance allows for an increase in the force (load) while maintaining the same moment. Hence, the