12 SMSS Prelim 2010 4E Physics P2 QP

Name: …………………………………….……….. Reg. No. ………… Class: ………….… Secondary 4 Express 17th September 2010 Duration : 1 hour 45 minutes Total Marks : 80 READ THESE INSTRUCTIONS FIRST Do not open this Booklet until you are told to do so. Write your name, register number and class in the spaces at the top of this page and on any separate writing paper used. Write in dark blue or black pen. 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 all questions. Question 11 has a choice of parts to answer. Write your answers to Section A and to Questions 9 and 10 in the spaces provided on the Question Paper. Write your answer to Question 11 on the lined pages and, if necessary, continue on the separate Answer Paper provided. At the end of the examination, fasten all your work securely together. Candidates are reminded that all quantitative answers should include appropriate units. Candidates are advised to show all their working in a clear and orderly manner, as more marks are awarded for sound use of physics than for correct answers. The number of marks is given in brackets [ ] at the end of each question or part question. When necessary, assume the acceleration due to gravity, g to be 10 m/s 2. ________________________________________________________________________ This question paper consists of 19 printed pages PHYSICS 5058/02 St. Margaret’s Secondary School Preliminary Examinations 2010 [Turn over

2 Section A Answer all the questions in this section. 1 Fig. 1.1 shows an archer drawing back a bow to shoot an arrow horizontally towards a target. When he releases the arrow, it is accelerated over a distance of 0.40 m by the bow. It leaves the bow with a speed of 80.0 m/s, heading on a direct line to the centre of the target which is 16.0 m away. Assume that air resistance is negligible and that the arrow hits the target. (a) Calculate the time taken for the arrow to travel the distance of 0.40 m from release by the archer until the arrow just leaves the bow. Assume that the arrow has constant acceleration over this time. time = s [2] (b) Calculate the magnitude of the acceleration of the arrow over the 0.40 m in part (a). acceleration = m/s2 [2] 16.0 m Fig. 1.1

3 (c) Sketch a speed-time graph of the motion of the arrow in Fig. 1.2 below. Your graph should start at the time when the archer releases the arrow and end after the arrow has hit the target. Label your graph appropriately, indicating clearly when the arrow leaves the bow and when the arrow hits the target. Fig. 1.2 [4]

4 2 Fig. 2.1 shows a child sitting on a child seat and Fig. 2.2 shows a simplified drawing of the same child seat. The total weight, W, of the child and the seat is 12.0 cm from C. (a) Draw on Fig. 2.2, the position of the force(s) that will hold the child seat in equilibrium. Indicate clearly the direction of this/these force(s). [1] Given that the total mass of the child and the seat is 10.8 kg, the length of BC is 70.0 cm and the horizontal distance AB is 60.0 cm, calculate (b) the total weight, W of the child and the seat, weight = N [1] Fig. 2.1 45 ° W Fig. 2.2 A B C

5 (c) the force(s) needed to keep the child seat in equilibrium when the child is on it. force = N force (if any) = N [4]

6 3 Fig. 3.1 shows water held by a dam. The maximum depth of the water is 120 m. Water flowing through the pipe passes through the turbine and generates electricity. The density of water is 1000 kg/m3. (a) Determine the pressure due to the water at the base of the dam. pressure = Pa [2] (b) Explain why the dam is thicker at the base than at the top. [2] (c) (i) Determine the speed of the water hitting the turbine. speed = m/s [2] pipe turbine 120 m Fig. 3.1 100 m water

7 (ii) If the turbine is only able to convert 60 % of the supplied energy into electrical energy, calculate the power generated, given that the rate of water hitting the turbine is 3600 kg/s. power = W [2] 4 Fig. 4.1 shows a sealed syringe that contains gas, at atmospheric pressure and many very small dust particles suspended in the gas. The piston moves freely along the cylinder without any friction. No gas can escape. (a) Explain why the dust particles stay suspended in the gas and do not fall to the bottom of the syringe. [2] (b) As the syringe is heated, the piston moves outwards and stops moving when the temperature is steady. Using the kinetic model, explain (i) why the piston moves outwards, [1] (ii) why the piston stops moving. [2] Fig. 4.1

8 5 Fig. 5.1 shows a ray of monochromatic light incident on an interface of air and corn oil at an angle of 35°. The ray is transmitted through parallel layers of corn oil and glycerol and is then reflected from the surface of a plane mirror, located below and parallel to the glycerol layer. The ray then emerges from the corn oil back into the air at point P. The refractive index of corn oil is 1.47. (a) Calculate the angle of refraction of the light ray as it enters the corn oil from air. angle = ° [2] (b) The ray does not bend at the corn oil and glycerol interface. Explain why. [2] (c) Complete the ray diagram in Fig. 5.1 to show how the refracted ray leaves p o i n t P . [ 1 ] Fig. 5.1

9 (d) Will the reflected ray from the mirror ever go through total internal reflection at point P if we vary the angle of the incident ray in air? Explain your answer. [3] 6 Fig. 6.1 shows a negatively charged rod lowered into an uncharged metal can standing on an insulating slab. (a) Indicate on Fig. 6.1, the distribution of charges produced on the can. [1] (b) The outside of the can is then touched with a wire connected to earth in Fig. 6.2. Explain the effect this will produce on the charges on the can? [2] (c) Can the same effect in part (a) be produced if the insulated charged rod is replaced with a metal rod held in the hand of a student? Explain your answer. [2] Fig. 6.1 Fig. 6.2

10 7 Fig. 7.1 shows an electrical circuit containing four resistors R 1, R 2, R 3 and R 4 connected to a 12 V battery of negligible internal resistance. (a) Calculate the effective resistance of the circuit. effective resistance = Ω [2] (b) Determine the value of I 1, I2 and I3. I 1 = A I 2 = A I 3 = A [3] Fig. 7.1