YHSS 4NA Prelim 2022 MS

1 YHSS 4NA Prelims 2022 5105 Paper 1 [20 marks] 1 B 11 D 2 C 12 D 3 D 13 C 4 C 14 A 5 B 15 C 6 B 16 C 7 B 17 C 8 C 18 D 9 D 19 D 10 A 20 B

2 YHSS 4NA Prelims 2022 5105 [Overall just 1 m deducted from Paper 2 for units error] Paper 2 Section A [14 marks] 1 (a) W = mg = (120)(10) = 1200 N (1 m for substitution, 1 m for final answer) [2] (b) By Principle of Moments, 𝐶𝑊𝑀 = 𝐴𝐶𝑊𝑀 (1200)(0.80) = (𝐹)(0.80 + 0.50) 960 = 1.30𝐹 𝐹 = 960 1.30 = 738 𝑁 (1 m for substitution, 1 m for final answer) [2] Total marks = 4 2 (a) 3 x 108 m/s [1] (b) 𝑓 = 𝑣 𝜆 = 3 × 108 0.1 × 10−9 = 3 × 1018 𝐻𝑧 (1 m for correct substitution, 1 m for correct answer) (if prefix not considered, max of 1m) [2] (c) frequency of gamma rays compared to X-rays Higher wavelength of gamma rays compared to X-rays Lower / shorter speed of gamma rays in vacuum compared to X-rays Same / Equal [2] Total marks = 5 3 (a) 𝑅𝑒𝑓𝑓𝑒𝑐𝑡𝑖𝑣𝑒 = 3 + (1 4 + 1 4) −1 = 5 Ω (1 m for correct substitution, 1 m for correct answer) [2] (b) 𝐼 = 𝑉 𝑅 = 6 5 = 1.2𝐴 (1 m for correct substitution, 1 m for correct answer) [2] (c) Increase (resistors connected in parallel have a lower effective resistance, thus the current would increase) [1] Total marks = 5

3 YHSS 4NA Prelims 2022 5105 Paper 2 Section B [16 marks] 4 (a) (i) 101.905 s [1] (ii) 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑠𝑝𝑒𝑒𝑑 = 𝑡𝑜𝑡𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑡𝑜𝑡𝑎𝑙 𝑡𝑖𝑚𝑒 = 5.063 × 103 101.905 = 49.7 𝑚/𝑠 (Allow for ECF from (a)(i)) (1 m for correct substitution, 1 m for correct answer) (1 m awarded if students do not convert km to m, but show workings) [2] (b) 𝑎 = 𝑣 − 𝑢 𝑡 = 55 − 0 7 = 7.86 𝑚/𝑠2 (1 m for correct substitution, 1 m for correct answer) [2] (c) 𝐹 = 𝑚𝑎 = (920)(7.86) = 7230 𝑁 (1 m for correct substitution, 1 m for correct answer) [2] (d) Stopping distance would increase, due to the decreased friction between the tyres and the road/brakes Total marks = 8 5 (a) X marked between 2 and 6 minutes [1] (b) solid state liquid state arrangement of molecules Closely packed in an orderly arrangement Closely packed, disorderly/no long range order movement of molecules Vibrates about a fixed position Slip and slide over each other 1m for each correct description [4] (c) (i) 1 m for every 4 points plotted correctly If students make a mistake for 1 point, can still award 2 m [2] (ii) Curved line of best fit drawn correctly [1]

4 YHSS 4NA Prelims 2022 5105 (iii) The liquid evaporates / Some molecules escape from the surface of the liquid / Any reasonable answer [1] Total marks = 8 6 (a) Neutral Blue [1] (b) (i) 𝑄 = 𝐼𝑡 = (14.2)(5 × 60) = 4260 𝐶 (1 m for correct substitution, 1 m for correct answer) If students show substitution but did not convert time to seconds, to award 1 m. [2] (ii) 𝑃 = 𝐼𝑉 = (14.2)(240) = 3410 𝑊 (1 m for correct substit