2020 YIJC H1 Physics Prelims P2 Questions

©YIJC [Turn over YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CANDIDATE NAME CG INDEX NUMBER PHYSICS Paper 2 Structured Questions Candidates answer on the Question Paper. No Additional Materials are required. 8867/02 2 September 2020 2 hours READ THESE INSTRUCTIONS FIRST This document consists of 18 printed pages and 2 blank pages. For Examiner’s Use Paper 2 Section A 1 /8 2 /6 3 /10 4 /9 5 /11 6 /16 Section B 7 /20 Penalty Paper 2 Total /80 Write your name and class in the spaces at the top of this page. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid/tape. The use of an approved scientific calculator is expected, where appropriate. Section A Answer all questions. Section B Answer one question. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question.

2 ©YIJC 8867/02/YIJC/20 [Turn over Data speed of light in free space c = 3.00  108 m s−1 elementary charge e = 1.60  10−19 C unified atomic mass constant u = 1.66  10−27 kg rest mass of electron me = 9.11  10−31 kg rest mass of proton mp = 1.67  10−27 kg the Avogadro constant NA = 6.02  1023 mol1 gravitational constant G = 6.67  1011 N m2 kg2 acceleration of free fall g = 9.81 m s−2 Formulae uniformly accelerated motion s = ut + 2 1 at2 v2 = u2 + 2as resistors in series R = R1 + R2 +………. resistors in parallel R 1 ........11 21  RR =

3 ©YIJC 8867/02/YIJC/20 [Turn over Section A Answer all the questions in this section. 1 A uniform plank AB of length 5.0 m and weight 200 N is placed across a stream, as shown in Fig. 1.1. Fig. 1.1 A man of weight 880 N stands at a distance x from end A. The ground exerts a vertical force FB on the plank at end B. As the man moves along the plank, the plank is always in equilibrium. (a) (i) Draw all other forces on the plank and label them clearly. [3] (ii) Define moment of a force. …….………………………………...…………………………………………..………… …….………………………………...…………………………………………..………… ………………………………….…………………...…………………………………. [1] A

4 ©YIJC 8867/02/YIJC/20 [Turn over (iii) The man stands at a distance x = 0.50 m from end A. Calculate the magnitude of FB. FB = ………………….. N [2] (b) If the plank is not uniform and the centre of gravity is nearer to point B, explain why the magnitude of FB will increase. ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..………………… [2] [Total: 8]

5 ©YIJC 8867/02/YIJC/20 [Turn over 2 Fig. 2.1 shows an archer with a bow. The force F required to bend the bow and the corresponding displacement d of the arrow are measured. A plot of F against d is shown in Fig. 2.2. Fig. 2.2 250 200 150 100 50 0 F / N 0 0.2 0.4 0.6 d / m d Fig. 2.1

6 ©YIJC 8867/02/YIJC/20 [Turn over (a) An experienced archer is able to draw an arrow further back, resulting in a greater displacement of arrow, d, as compared to a novice archer. Using Fig. 2.2 and the principle of conservation of energy, suggest an advantage that this extra displacement provides. ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..………………… [2] (b) (i) Using Fig. 2.2, estimate the elastic potential energy stored in the bow when an arrow is displaced by 0.50 m. elastic potential energy = ………………………… J [2] (ii) The arrow in (b) (i) is then released by the archer from the bow. Determine the maximum speed of the arrow which has a mass of 3.5  10−2 kg. maximum speed = ………………………… m s−1 [2] [Total: 6]

7 ©YIJC 8867/02/YIJC/20 [Turn over 3 (a) Explain qualitatively why a body which is travelling in circle with constant speed experiences an acceleration towards the centre of the circle. ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..……………………… ………………………………...…………………………………………..………………… [2] (b) A toy plane has a mass of 0.40 kg as shown in Fig. 3.1, and a taut wire of length 5.0 m attached to it when it flies in a horizontal circle. The taut wire is inclined 60 ° to the horizontal and fixed to a point O. The wings of the toy plane are horizontal, creating a vertical upward lift on the plane. Fig. 3.1 (i) If each revolution takes 3.5 s, determine the centripetal acceleration of the toy plane. centripetal acceleration = ………………………… m s−2 [2]

8 ©YIJC 8867/02/YIJC/20 [Turn over (ii) Calculate the tension T in the taut wire. T = ………………………… N [2] (iii) Hence calculate the upward lift L on the toy plane due to the air. L = ………………………… N [2] (iv) In another arrangement, t he taut wire is now fixed to a point O attached to the ceiling with the toy plane flying in a horizontal circle as shown in Fig. 3.2. Fig. 3.2 Given that the magnitude of tension in wire remains unchanged, discuss how your answer to (b) (iii) will change if the wings of the toy plane are horizontal and the wire remaining at 60o to the horizontal. ………………………………...…………………………………………..……………… ………………………………...…………………………………………..……………… ………………………………...…………………………………………..……………… ………………………………...…………………………………………..…………… [2] [Total: 10]

9 ©YIJC 8867/02/YIJC/20 [Turn over 4 A battery of electromotive force (e.m.f.) E and internal resistance 1.5 Ω is connected to a network of resistors, as shown in Fig. 4.1. Fig. 4.1 Resistor X has a resistance of 8.0 Ω. Resistor Y has a resistance of 2.0 Ω. Resistor Z has a resistance of RZ. The current in X is 0.60 A and the current in Y is 1.8 A. (a) Calculate (i) the current I in the battery, I = ………………………… A [1] (ii) resistance RZ and RZ = ………………………… Ω [2]

10 ©YIJC 8867/02/YIJC/20 [Turn over (iii) e.m.f. E. E = ………………………… V [2] (b) Resistors X and Y are each made of wire. The two wires have the same length and are made of the same metal. Determine the ratio cross-sectional area of wire X cross-sectional area of wire Y . ratio = ………………………… [2] (c) Determine the efficiency of the battery. efficiency = ………………. [2] [Total: 9]