2022 NYGH Phy Prelims P2

南洋女子中学校 NANYANG GIRLS' HIGH SCHOOL Preliminary Examination 2022 Secondary Four 'O' Level CANDIDATE NAME CENTRE NUMBER S INDEX NUMBER PHYSICS 6091/02 Paper 2 29 Aug 2022, Monday 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, index number and name on all the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Sections A and B Answer all questions. Question 13 has a choice of parts to answer. Write your answers in the spaces provided on the Question Paper. Electronic calculators may be used. You are advised to spend no longer than one hour on Section A and no longer than 45 minutes on Section B. At the end of examination fasten all your work securely together. The number of marks is given in the brackets [ ] at the end of each question or part question. Examiner’s Use Paper 1 Section A 1 2 3 4 5 6 7 8 9 10 Section B 11 12 13 Total 120 % Setter: CMH This document consists of 21 printed pages and 3 blank pages. [Turn over

2022 Preliminary Examination Secondary 4 2 Nanyang Girls’ High School Setter: CMH Physics II Section A (50 marks) Write your answers in the spaces provided. 1 A 30 N block is suspended from a ceiling with two cables, C1 and C2, as shown in Fig. 1.1. Fig. 1.1 ( a ) On Fig. 1.1, draw and label the forces acting on the block. [1] ( b ) With the aid of a scale diagram, determine the magnitude of the forces acting along C 1 and C2. magnitude of force along C 1 = magnitude of force along C2 = [3] ceiling 110 °100 ° block C2 C1

2022 Preliminary Examination Secondary 4 3 Nanyang Girls’ High School Setter: CMH Physics II [ Turn over 2 A children’s ride consists of a steel cable running between two posts of different heights as shown in Fig. 2.1. A girl starts the ride from rest at the higher post. Her horizontal motion has an initial uniform acceleration for 3.0 s followed by a constant speed of 2.4 m/s for a further 5.0 s before coming to rest at the lower post after decelerating for the last 1.0 s. ( a ) What does uniform acceleration mean? [1] ( b ) On Fig. 2.2, draw a speed-time graph for the horizontal motion of the girl. [2] ( c ) Calculate (i) the horizontal distance travelled by the girl, horizontal distance = [2] Fig. 2.1 steel cable wheel post speed m/s time s Fig. 2.2 7.0 m 4.0 m

2022 Preliminary Examination Secondary 4 4 Nanyang Girls’ High School Setter: CMH Physics II ( i i ) the average horizontal speed for the whole ride. average speed = [1] ( d ) If conservation of gravitational potential energy and kinetic energy of the girl is assumed, calculate the speed of the girl when she reaches the lower post. speed = [2] 3 A student wishes to confirm the density of an aluminum rod, given as 2.7 g/cm3. She measures the mass of the rod to be 86.4 g. She then places the rod into a measuring cylinder filled with 40 cm3 of water. ( a ) If the given density of aluminum is true, determine the final reading on the measuring cylinder when the rod is fully immersed in the water. final reading on measuring cylinder = [2] ( b ) State how the density of the rod will change if the rod is placed in hot water. [1]

2022 Preliminary Examination Secondary 4 5 Nanyang Girls’ High School Setter: CMH Physics II [ Turn over 4 Fig. 4.1 shows a system for raising a piece of metal weighing 2000 N. The piece of metal is freely pivoted at A. Fig. 4.1 A man pulls on the rope with a force F and keeps the piece of metal in equilibrium in the position shown in Fig. 4.1. (a) By taking moments about A, calculate the force F. F = [2] (b) As the piece of metal rotates anti-clockwise, explain how the force required to keep the piece of metal in equilibrium changes. [2] rope 8.0 m 2.0 m 2000 N piece of metal F A

2022 Preliminary Examination Secondary 4 6 Nanyang Girls’ High School Setter: CMH Physics II 5 A water wave passes a floating log as shown in Fig. 5.1. Fig. 5.1 The log is 6.0 m long and 5 complete waves pass the end X of the log in 12.5 s. (a) Describe how the motion of the water particles tells us that the water wave is a transverse wave. [1] (b) Determine ( i ) the wavelength of the wave, wavelength of the wave = [1] (ii) the frequency of the wave, frequency of the wave = [1] (iii) the speed of the wave. speed of the wave = [2] 6.0 m water wave log X

2022 Preliminary Examination Secondary 4 7 Nanyang Girls’ High School Setter: CMH Physics II [ Turn over 6 Fig. 6.1 below shows a scaled diagram of a laboratory thermometer L. The scale in °C is marked and a temperature reading of 28 °C is marked TL. (a) State the thermometric property for the thermometer shown in Fig. 6.1. [1] (b) Thermometer M is similar to L but has a different scale. The 50 °C mark on L corresponds to the 40 °C mark on M as shown in Fig. 6.2. Mark on thermometer M in Fig. 6.2, the position of the thread when the temperature is TL. Label this position TM. Show your working to determine the position of TM in the space below. [ 2 ] (c) When thermometer L is placed into a beaker of boiling water, the reading shows 100 °C as the water continues to be heated. Explain why the temperature does not rise although the water continues to be heated. [2] Fig. 6.1 L M Fig. 6.2 40 TL

2022 Preliminary Examination Secondary 4 8 Nanyang Girls’ High School Setter: CMH Physics II 7 Fig. 7.1 shows the top view of a shop floor. A shop staff at P monitors the display counter behind a wall using a plane mirror. Fig. 7.1 Answer the following questions on Fig. 7.1. (a) Locate the image of the corner of the display counter, Q in the plane mirror. Label the image R. [1] (b) Draw one light ray to show how an eye at P is able to see R. [1] (c) The plane mirror is too short to allow a staff at P to monitor the entire display counter. Draw one light ray to determine the minimum length of mirror required to monitor the entire display counter. Label the extension EF. [2] plane mirror P Q display counter wall

2022 Preliminary Examination Secondary 4 9 Nanyang Girls’ High School Setter: CMH Physics II [ Turn over 8 Fig. 8.1 below shows a home-made lightning alert device. It consists of two metal bells, A and B, which are mounted on insulating stands. An uncharged light metal sphere on the end of a nylon thread is free to swing about the point O. The bell B is connected to Earth. When a thundercloud is near, bell A becomes positively charged. The sphere then swings between A and B, striking the bells and causing them to ring. (a) Explain why the metal sphere moves towards A when a thundercloud is near. [2] (b) A typical lightning discharge has a current of 30 kA and takes an average time of 0.20 s to discharge. Calculate the amount of charge in a lightning flash. amount of charge = [2] metal bell B metal bell A nylon thread light metal sphere insulating stand lead to roof of house insulating stand O Fig. 8.1 O

2022 Preliminary Examination Secondary 4 10 Nany