Pure Physics Nov 2017_TYS ANSWERS

Nov 2017_Suggested ANSWERS_as at June 2023 Page 1 of 6 – Nov 2017 Catholic High School | O-Level Physics NOT IN SYLLABUS: 5059 Nov 2017 P1: - Suggested Answers P2: - Paper 1 [40 marks] 1 D 11 C 21 A 31 D 2 B 12 B 22 D 32 B 3 D 13 B 23 B 33 D 4 B 14 A 24 A 34 B 5 B 15 A 25 D 35 C 6 C 16 C 26 D 36 A 7 B 17 D 27 A 37 A 8 C 18 A 28 B 38 B 9 B 19 C 29 A 39 D 10 D 20 C 30 C 40 C *Q. 15: A The force per collision is greater (due to the gas molecules having greater speed). Since pressure of the gas remains the same, then the rate of collisions must have decreased. If the rate of collisions increased or stayed constant, the pressure would have increased given that the force per collision is greater. (Both B and C are incorrect.) *Q. 25: D Statement 1 was incorrect. The speed of light is 3.0 × 108 m/s only in vacuum. (B is incorrect.) *Q. 35: C If the question does not indicate otherwise , assume the resistance of a thermistor will increase with a decrease in temperature (i.e. when it is cold). The LDR would have low resistance when the surroundings are bright. (D is incorrect.) *Q. 40: C A decrease in the resistance of the cables as the cause of the more efficient transmission of electrical energy at high -voltage is a common misunderstanding. (B is incorrect.)

Nov 2017_Suggested ANSWERS_as at June 2023 Page 2 of 6 – Nov 2017 Paper 2 [80 marks] 1 a prefix symbol value milli m 10-3 mega M 106 kilo k 103 nano n 10-9 3 b acceleration density speed time volume weight 1 c Length of R = 5.4 cm Magnitude of R = 5.4 × 2.0 = 10.8 m/s (3 s.f.) 1 1 1 2 ai When an object is in equilibrium, the sum of clockwise moments about any point is equal to sum of anti- clockwise moments about the same point. 1 1 aii Taking moments about the wheels, Sum of clockwise moments = Sum of anticlockwise moments F1 × d1 = F2 × d2 12 × (21 + 4.0) = W × 4.0 W = 75.0 N (3 s.f.) 1 1 b With the heavier contents near the base, the centre of gravity of the suitcase is lower. The line of action of the weight is more likely to fall within the base area when the suitcase is tilted. 1 1 c The normal reaction (or contact) force acting on the suitcase by the ground. This force acts upwards (on the wheels of the suitcase), and is equal to the normal reaction (or contact) force acting on the ground by the suitcase. 1 1 3 ai The gas supply exerts a pressure on the water surface on the left that is greater than atmospheric pressure on the right.] 1 aii The gas pressure on the left is equal to the total pressure due to 9 cm of water column and atmospheric pressure. 1 b Pressure difference = hρg = [(17 - 8 )/100] × 1000 × 10 = 900 Pa (3 s.f.) 1 1 c Use a liquid of higher density (e.g. mercury). 1 horizontal velocity vertical velocity R

Nov 2017_Suggested ANSWERS_as at June 2023 Page 3 of 6 – Nov 2017 4 a Work done by a force