CJC H1 PHY P2 QP

1 [Turn over CATHOLIC JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS Higher 1 CANDIDATE NAME CLASS 2T INDEX NUMBER PHYSICS 8866/02 Paper 2 28 August 2015 2 hours Additional Materials: Answer Paper READ THESE INSTRUCTIONS FIRST Write your index number and name on all the work you hand in. Write in dark blue or black pen on both sides of the paper. [PILOT FRIXION ERASABLE PENS ARE NOT ALLOWED] You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A Answer all questions. Section B Answer any two questions. Circle the 2 questions that you answered in the table below. At the end of the examination, fasten all work securely together. The number of marks is given in brackets [ ] at the end of each question or part of the question. This document consists of 24 printed pages FOR EXAMINER’S USE SECTION A (40 MARKS) 1 /6 2 / 8 3 /7 4 /9 5 /3 6 /7 SECTION B (40 MARKS) 7 / 20 8 / 20 9 / 20 TOTAL /80

2 [Turn over PHYSICS DATA: speed of light in free space, c = 3.00 x 108 m s-1 permeability of free space, o = 4 x 10-7 H m-1 elementary charge, e = 1.60 x 10-19 C the Planck constant, h = 6.63 x 10-34 J s unified atomic mass constant, u = 1.66 x 10-27 kg rest mass of electron, me = 9.11 x 10-31 kg rest mass of proton, mp = 1.67 x 10-27 kg acceleration of free fall, g = 9.81 m s-2 PHYSICS FORMULAE: uniformly accelerated motion, s = u t + 2 1 a t2 v2 = u2 + 2 a s work done on / by a gas, W = p V hydrostatic pressure p = gh resistors in series, R = R1 + R2 + ... resistors in parallel, R 1 = ... 21 11 RR

3 [Turn over SECTION A (40 marks) Answer all questions in Section A. 1 A car of mass 1380 kg, travelling at 31.1 m s -1, is brought to rest by applying the brakes. The average braking force is estimated to be 1.38 x 104 N. (a) Calculate (i) the initial kinetic energy of the car, kinetic energy = ………………………..J [1] (ii) the average deceleration of the car, deceleration = ……………………… m s-2 [1] (iii) the distance travelled before it comes to rest. braking force = …………………………N [2] (b) Suggest whether the answer in (a)(iii) is an over-estimation or under-estimation. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… [2]

4 [Turn over 2 (a) State what is meant by the equilibrium of a body. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… [2] (b) Fig. 2 shows a girl supported by two ropes. She is in equilibrium. She has a weight of 392 N. Fig.2

5 [Turn over (i) Calculate the tension T1 and T2 in the ropes. tension T1 = ………………N tension T2 = ………………N [4] (ii) The girl is pulled vertically downwards so the ropes stretch. She is then released. Explain why the method you used in (i) could not be used to determine the tensions in the ropes immediately after she is released without additional information. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… [2]

6 [Turn over 3 A long -jumper leaps off the starting block at a speed 8.6 m s -1 at an angle  to the horizontal and lands on a level pit. (a) Explain why the longer-jumper needs to have an upwards component of velocity at take-off, as well as forward velocity component to reach a good horizontal distance. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… [2] (b) ((i) Suppose that the angle  = 35o, calculate the time to reach the maximum height and the horizontal distance of the long jumper. In your calculations, you should neglect the presence of air resistance. time = ……….……….s horizontal distance =……..…………..m [4] (ii) Why does his horizontal distance is less than the answer to (b)(i) when air resistance is taken into consideration. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… [1]

7 [Turn over 4 A glass tube of Helium gas atoms are excited when a potential difference is applied across it. When the emitted light is viewed through a spectrometer, three emission lines of blue, green and yellow colours are observed. Fig. 4.1 shows the spectral lines, together with the associated photon wavelengths of each colour. Fig. 4.1 Light from the gas is incident on the surface of a metal plate X. The electrons liberated from the plate are attracted to the anode as shown in Fig. 4.2 Fig 4.2 The experiment is then repeated using two other metal plates Y and Z of different work function energies. The table below shows the work function energies of the different plates. Plate Work Function Energy / eV X 1.58 Y 2.42 Z 3.17 (a) What is meant by the term work function energy of a metal? …………………………………………………………………………………………… …………………………………………………………………………………………… [1]

8 [Turn over …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… …………………………………………………………………………………………… [3] (b) The figure below shows the variation of current I in the circuit with applied potential difference V between the metal plate and anode when the blue light from the gas is allowed to incident on plate X. Fig. 4.3 (i) Calculate the stopping potential Vs. stopping potential Vs = ………………..V [3] (ii) On Fig. 4.3, sketch the variation of current I with applied potential difference V when the blue light from the gas is incident on plate Y. Assuming the intensity of the blue light remained constant. Explain your answers. V / V I / μA VS

9 [Turn over 5 Two wires X and Y, which are at right angles to the plane of the paper, carrying current I and 2I out of the plane of the paper as shown in Fig.5. A point P is at equal distance from the wires. On Fig. 5, draw an accurate vector diagram to show how you can determine the magnitude and direction of the resultant field at P. [3] Fig. 5 (iii) State with a reason, w hich of the plates used for the photoelectric effect experiments will a zero reading be registered in the micro-ammeter when all the 3 wavelengths are allowed to incident on the plates ? ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… [2] X Y P

10 [Turn over 6 In the 16 th century, Kepler conducted observations of the planetary positions and deduced that for a circular orbit of a planet around the Sun, if T is the period of rotation and r is the radius