HALF YEARLY EXAMINATIONS 2015/2016. Answer ALL questions showing your working Where necessary give your answers correct to 2 decimal places.

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1 Track 3 GIRLS SECONDARY, MRIEHEL HALF YEARLY EXAMINATIONS 2015/2016 FORM: 4 PHYSICS Time: 1½ hrs Name: Class: Answer ALL questions showing your working Where necessary give your answers correct to 2 decimal places. Table of Formulae Acceleration due to gravity g = 10 m/s² Average speed = total distance v = u + at a = (v u) total time t s = ut + ½at 2 s = (u + v)t v 2 = u 2 + 2as 2 Refractive index n = real depth Refractive index n = speed of light in air apparent depth speed of light in other medium Magnification = height of image = image distance from lens height of object object distance from lens Speed of wave v = fλ Periodic time T = 1 f Area of a triangle = ½bh Area of a trapezium = h(a + b) 2 For examiners use only Question Theory Practical Total Max. Mark Score Physics Form 4 Page 1 of 10 Half-Yearly T

2 SECTION A This section carries 40 marks 1. This question is about the properties of waves. The figure below shows a displacement-distance graph. a) How many waves are shown? [1] b) On the above diagram mark the amplitude of the wave (mark as a ). [1] c) What is the wavelength of the wave? [1] d) Describe the term periodic time? [1] e) If 40 waves pass through a point in 2 minutes. Calculate the frequency of the wave. [2] f) Work out the velocity of the above wave in m/s. [2] Physics Form 4 Page 2 of 10 Half-Yearly T

3 2. This question is about properties of light In an experiment, a ray is directed towards a semi-circular glass block at three different angles 30, 42 and 60 as shown in figures 1, 2 and 3. The critical angle of the glass block is 42. air glass 30 air glass 42 air glass 60 figure 1 figure 2 figure 3 a) The critical angle of the glass block is the angle of incidence in glass at which the angle of refraction is. [1] b) The speed of the light ray in the glass block is (smaller than, greater than, equal to) the speed of light in air. [1] c) Complete the rays of light in figures 1, 2 and 3. [3] d) When the angle of incidence in the glass block is greater than the critical angle, then occurs. In practice, this effect is used in and. [3] 3. This question is about linear motion An aeroplane on its take-off run has a uniform acceleration of 2.8 m/s 2 for 40 s until it finally lifts off the ground. a) What is the initial velocity of the aeroplane? [1] b) Calculate the velocity reached by the aeroplane immediately before its take-off. [2] c) Find the distance travelled during the 40 s period. [2] Physics Form 4 Page 3 of 10 Half-Yearly T

4 d) Sketch the velocity-time graph for the motion of the aeroplane before take-off, showing the final velocity reached and the time taken to reach this velocity. Label the axes. [3] 4. This question is about waves A fish appears to be at a different depth when observed from above as shown in the diagram. The table shows how the real and apparent depths of the fish change. Real depth (cm) Apparent depth (cm) a) Plot a graph of real depth (on x-axis) against apparent depth (on y-axis). [5] b) From the graph, when the fish is at a depth of 55 cm, it appears to be at a depth of. [1] c) Find the refractive index of water. [2] Physics Form 4 Page 4 of 10 Half-Yearly T

5 5. This question is about electromagnetic spectrum Gamma Rays X-rays Ultraviolet Infrared Radiowaves a) Complete the following list of electromagnetic waves in order of increasing wavelengths. [1] b) Electromagnetic waves are waves. [1] c) Name one other common property to all electromagnetic waves. [1] d) Which part of the electromagnetic spectrum : (i) is used to cure cancer, [1] (ii) is emitted by warm objects, [1] (iii) is stopped by the ozone layer in the atmosphere? [1] e) X-rays pass through human tissues but are stopped by the. [1] f) Name one precaution to be taken when using X-rays. [1] Physics Form 4 Page 5 of 10 Half-Yearly T

6 velocity (m/s) SECTION B This section carries 45 marks 6. This question is about velocity-time graphs The following velocity-time graph represents the motion of a football player moving in a straight line during part of a match. 8 C D B 0 A time (s) 8 10 E a) The player s acceleration is negative in section. This negative acceleration is also called. [2] b) The player s acceleration in section CD is because the player is moving at. [2] c) In which section does the player have the maximum acceleration? Explain why. [2] d) Calculate the player s maximum acceleration during his motion. [2] e) Using the graph, find the distance travelled by the player in the last 6 seconds. [2] Physics Form 4 Page 6 of 10 Half-Yearly T

7 f) Hence, calculate the average velocity of the player during the last 6 seconds. [2] g) Sketch a distance-time graph for the motion of the player during the last 6 seconds showing the total distance covered and the time taken to cover this distance. Label the axes. [3] 7. This question is about the properties of light Lara wants to investigate the path of a ray of light when it is directed towards a plane mirror. She expects to find a relationship between the angles of incidence and reflection for a plane mirror. a) i) State the two laws of reflection for a plane mirror. [2] ii) Draw a labelled diagram of the experimental setup used by Lara, including any rays. [2] Physics Form 4 Page 7 of 10 Half-Yearly T

8 iii) Briefly describe the steps Lara needs to follow in order to perform the experiment. [4] iv) List one precaution that Lara needs to follow during this investigation. [1] b) Lara then experiments with a convex lens. She placed an object of height 1.3 cm in front of the lens. Note: 1 square represents 1 cm. O F F i) Complete the ray diagram by drawing two rays on it and hence draw the image produced by the lens. [3] ii) Write down two properties used to describe the image obtained. [2] iii) Mention one practical use of the above lens arrangement. [1] Physics Form 4 Page 8 of 10 Half-Yearly T

9 8. This question is about waves On her way to the school, Ella was listening to her favourite song on the radio. Waves can either be transverse or longitudinal. a) Describe the difference between these two types of waves. [2] b) Sound wave is a wave. [1] c) A human ear can hear sounds of frequency up to 20 KHz. i) 20 KHz = Hz. [1] ii) Give the name for sound waves having frequency above 20 KHz. [1] d) This type of sound is used by ships to measure the depth of water beneath them. If the speed of sound in sea water is 1500 m/s and the time taken for the sound to return after emission is 5 s, calculate the depth of the water. [2] e) What do we call the reflection of a sound wave? [1] f) At school, Ella placed two barriers in a ripple tank leaving a gap between them as shown. Physics Form 4 Page 9 of 10 Half-Yearly T

10 i) Measure the wavelength of the incident waves. [1] ii) Complete the diagram to show what happens to the water waves after they pass through the gap. [2] iii) What is the wavelength of the waves after passing through the gap? [1] iv) Give a name for this property of wave. [1] g) The same experiment was repeated, but this time a piece of glass was immersed (placed) in the ripple tank such that the wavefronts before the barrier travel in deep water and those after the barrier travels in shallow water. Draw the new wavefronts observed in the ripple tank. [2] END OF PAPER PLEASE CHECK YOUR WORK! Physics Form 4 Page 10 of 10 Half-Yearly T