EJC 2019 J1H2 Promo MS (Final)

© EJC 2019 9749/01/J1H2PROMO/2019 EUNOIA JUNIOR COLLEGE JC1 PROMOTIONAL EXAMINATIONS 2019 General Certificate of Education Advanced Level Higher 2 PHYSICS Multiple-Choice & Structured Questions MARK SCHEME w/ EXAMINERS’ COMMENTS Maximum Mark 9749 September / October 2019 Paper 1 Answer Key 1 2 3 4 5 6 7 8 9 10 B C D A D C B C D B 11 12 13 14 15 16 17 18 19 20 C B C C D B D B D A 21 22 23 24 25 26 27 28 29 30 C D A C A B A B A C

2 © EJC 2019 9749/J1H2PROMO/2019 Paper 2 Mark Scheme 1 (a) (i) Gradient of tangent (at t = 10 s) = (100-0)/(10-6) = 25 m s-1 M1 A1 (ii) By Principle of conservation of energy Loss in Ep = Gain in Ek (0.55) mgh = ½ mv2 (0.55)(9.81)h = ½ (25)2 h = 57.9 = 58 m (2 s.f) M1 A1 (b) (i) All 3 forces (Normal Contact, Weight, Resistive Force) drawn and labelled correctly. B1 (ii) The resultant force acting on the skier is downwards and parallel along the slope. Hence the skier experienced an acceleration, resulting in an increased in speed. This explains the increasing rate of change of distance with time shown in the graph. B1 B1 (c) (i) s = ut + (0.5)at2 80 = (0.5)(9.81)(t2) t = 4.0 s A1 (ii) x = vt = 25(4.0) = 100 m A1 Normal contact force Friction and/or air resistance Weight

3 © EJC 2019 9749/J1H2PROMO/2019 Examiners’ Comments (a) (i) Many candidates incorrectly used s = ½ (u + v)t to solve the problem. They cannot assume that the curve graph is parabolic and that the acceleration is constant. Some candidates incorrectly used the relationship speed = total distance / total time which gives the average speed. The tangent at t = 10 s were absent in many scripts. Working for the gradient of the tangent are often missing. (ii) Presentations were often poor and lacking in the concept being used. Candidates should write down the physics concepts used and the required equations. Candidate often substituted numbers without the equation. Many candidates missed out or wrongly used the 55% value given in the question. They used 55% of the kinetic energy instead. Candidates should have checked their working again when they get small values of the ramp height. (b) (i) Some candidates missed out the air resistance, friction, and normal contact force. Some of the weight and normal contact force were drawn in the wrong direction. Some wrongly drew the forward force. Some candidates did not label in full. Relative length of the arrows drawn is expected. (ii) Many candidates failed to explain the presence and direction of the resultant force. Explanations were often vague and not coherent. Some used energy concepts to explain the graph which were not the required answers. They should use the idea of the resultant force to bring about the idea of acceleration which then lead to the increasing speed as shown i