EJC Physics 2021 J2 H1 MYE P2 (Printed)

©EJC 2021 8867/02/J2H1MYE/2021 [Turn over EUNOIA JUNIOR COLLEGE JC2 Mid-Year Examination 2021 General Certificate of Education Advanced Level Higher 1 CANDIDATE NAME CIVICS GROUP 2 0 - REGISTRATION NUMBER PHYSICS Paper 2 Longer Structured Questions 8867/02 02 July 2021 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, civics group and registration number on all the work you hand in. 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 paper clips, highlighters, glue or correction fluid. The use of an approved scientific calculator is expected where appropriate. Section A Answer all questions. Section B Answer one question only You are advised to spend one and a half hours on Section A and half an hour on Section B 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. This document consists of 23 printed pages and 1 blank page. For Examiner’s Use Section A 1 2 3 4 5 6 Section B 7 8 Total

2 ©EJC 2021 8867/02/J2H1MYE/2021 Data Formulae uniformly accelerated motion, s = ut + ½at2 v2 = u2 + 2as resistors in series, R = R1 + R2 + … resistors in parallel, 1/R = 1/R1 + 1/R2 + … 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

3 ©EJC 2021 8867/02/J2H1MYE/2021 [Turn over Section A Answer all the questions in this Section in the spaces provided. 1 (a) Define acceleration. ………………………………………………………………………………………………………… …………………….…………..……………………………………………………………………[1] (b) The displacement s moved by an object in time t may be given by the expression 212s ut at= + where a is the acceleration of the object. State one condition for this expression to apply to the motion of the object. ……………………………………………………….……………………………………………..[1] (c) A rock rolls down the slope of a cliff, inclined at 20 o, and leaves the cliff at a speed of 50 m s−1 as shown in Fig 1.1. The rock lands onto another cliff that is at a horizontal distance of 25 m away from the first one. Fig. 1.1 (i) Calculate the duration of time that the rock experiences free fall. time = ……………………… s [2]

4 ©EJC 2021 8867/02/J2H1MYE/2021 (ii) Determine the angle, below the horizontal, of the direction of the rock’s velocity upon landing. angle = ……………………………… o [3] (iii) A bridge connecting the edge of one cliff to the other is being proposed. Calculate the minimum length of the bridge required. length = ……………………… m [3]

5 ©EJC 2021 8867/02/J2H1MYE/2021 [Turn over (iv) On the axis of Fig. 1.2, sketch graphs to represent, during free fall, the variation with time of the rock’s 1. vertical velocity and label this graph A [1] 2. horizontal velocity and label this graph B [1] You are not required to state values on the axes. Fig 1.2 [Total: 12] velocity time 0

6 ©EJC 2021 8867/02/J2H1MYE/2021 2 (a) State the Principle of Conservation of Momentum. ……………………………………………………………………….……………………….………. ……………………………………………………………………….……………………….………. ………………………………………………………………………………..…………………... [1] (b) Two objects X and Y, with masses 2.0 × 10 3 kg and 3.0 × 103 kg respectively, traveling in the same direction collides head- on. Fig. 2.1 shows how the momentum of X varies with time. Fig 2.1 (i) Using information from Fig. 2.1, determine the change in momentum of X. change in momentum of X = ……………………… kg m s −1 [1] (ii) Object Y was traveling at a speed of 10 m s−1 before the collision. On Fig. 2.1, sketch the graph showing how the momentum of Y varies with time for the same time period. [2] (iii) State and explain quantitatively whether the collision of the two objects is an example of an elastic collision. ……………………………………………………………………………………….………. ……………………………………………………………………………………….………. ……………….……………………………………………………………….................. [2] momentum / 103 kg m s−1 time / s 0 0.4 20 40 60 0.0 0.8 1.2 1.6 X

7 ©EJC 2021 8867/02/J2H1MYE/2021 [Turn over (iv) Object Z has mass m and speed v as shown: m = (1240 ± 20) kg v = (22.2 ± 0.8) m s−1 Calculate the kinetic energy of object Z together with its associated uncertainty in kJ. kinetic energy of object Z = ……………………. ± .……………… kJ [3] [Total: 9]

8 ©EJC 2021 8867/02/J2H1MYE/2021 3 A lorry moves up a road that is inclined at 9.0° to the horizontal, as shown in Fig. 3.1. The lorry has mass 2500 kg and the force due to air resistance is negligible. Fig 3.1 (a) At an instant in time, the lorry is travelling with an acceleration of 2.0 m s −2 at a speed of 8.5 m s−1. Calculate the instantaneous power from the engine to move the lorry up the road. power = …………..………. W [3] (b) The truck reaches a speed of 12 m s−1 when the driver jams on the brakes. The truck skidded with a kinetic friction of 500 N. Calculate the distance travelled by the truc k before it reaches a speed of 8.0 m s −1 where he regains control of the truck. distance = ………………………. m [2] [Total: 5]

9 ©EJC 2021 8867/02/J2H1MYE/2021 [Turn over 4 (a) A satellite is in a circular orbit of radius r about the Earth of mass M, as illustrated in Fig. 4.1. Fig. 4.1 The mass of the Earth may be assumed to be concentrated at its centre. Show that the period T of the orbit of the satellite is given by the expression 2 23 4πT= r GM where G is the gravitational constant. Explain your working. [2] (b) State two features of a geostationary satellite. 1. …………………………………………………………………………………...………………… 2. …………………………………………………………………………………………...…….. [2] (c) The mass M of the Earth is 246.0 10 kg× . Calculate the speed of a geostationary satellite. speed = ……………………… m s −1 [3] (d) Explain why the geostationary satellite can be described as being weightless. ……………………………………………………………………………………………...………… …………………………………………………………………………………………………….. [2] [Total: 9]

10 ©EJC 2021 8867/02/J2H1MYE/2021 5 An electron travelling at a uniform speed of 1.5 × 107 m s-1 in vacuum enters the gap between two plane, parallel deflection plates along the line PQ, mid- way between the plates as shown in Fig. 5.1. The plates are 40 mm long and 20 mm apart, with the upper plate being at a positive potential V with respect to the lower one. The electron emerges from the plates at R with a velocity of 1.6 × 107 m s-1 at an angle of 20o to its original direction. Fig. 5.1 (a) (i) Calculate the time taken by the electron to travel from Q to R. time taken =…………..………. s [1] (ii) 1. Calculate the magnitude of the change in velocity ∆v of the electron during its path between Q and R. ∆v = ………………………. m s -1 [2] 40 mm P Q 0 V R +V 20 mm 1.6 × 107 m s-1 1.5 × 107 m s-1 20o