UNIQUE SCIENCE ACADEMY

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1 1 UNIQUE SIENE EMY Test (Unit 13) Name :... Paper: Physics ate :... lass: 2( Jj Time llowed: 35Minutes Maximum Marks: 25 [Total 17 Marks] 1 Theory Section: tuning fork produces a longitudinal wave of frequency 440 Hz. The wave travels through air with a speed of 330 m / s. (a) Explain what is meant by a longitudinal wave.... [1] (b) alculate the wavelength of the wave. 2 wavelength =... m [2] [Total: 3] Fig. 2.1 shows ripples travelling across the surface of a lake. undisturbed surface Fig. 2.1 (a) What property of the ripples means that a transverse wave motion is formed?... [1] (b) The frequency of the wave is 3 Hz. On Fig. 2.1, mark a distance which shows how far the ripples travel in 1 second, and explain how you obtain your answer.... [2] [Total: 3]

2 2 2 Observations of a distant thunderstorm are made. (a) uring a lightning flash, the average wavelength of the light emitted is m. This light travels at m/s. alculate the average frequency of this light. frequency =... [2] (b) The interval between the lightning flash being seen and the thunder being heard is 3.6 s. The speed of sound in air is 340 m/s. (i) alculate the distance between the thunderstorm and the observer. distance =... (ii) Explain why the speed of light is not taken into account in this calculation [3] oy throws a large stone into a large still pond, as illustrated in Fig.3.1. [Total: 5] Fig. 3.1

3 3 (a) Girl hears the plop sound of the stone entering the water a very short time after she sees the splash, but it is many seconds before the water wave reaches the edge of the pond where she is sitting. Use this information to decide which wave travels fastest and which travels slowest. Write fastest in one box and slowest in another box. Leave one box empty. sound wave light wave water wave [2] (b) In the boxes below, state whether each type of wave is a transverse or a longitudinal wave. sound wave light wave water wave [3] (c) 1 2 In the boxes below, put a tick alongside any of the types of wave that do not need a substance in which to travel. sound wave light wave water wave [1] MQ SETION: [Total 8 Marks] surf-board moves at a speed of 10 m/s on the crest of a wave. The distance between wave crests is 10 m. What is the frequency of the wave motion? 1Hz 4Hz 20Hz 10 Hz The diagram shows the cross-section of a water wave. Which distance is the amplitude of the wave? [Total: 6]

4 4 3 drop of water from a tap falls onto the surface of some water of constant depth. view from above Water waves spread out on the surface of the water. Which statement is true? The waves are longitudinal and travel at the same speed in all directions. The waves are longitudinal and travel more quickly in one direction than in others. The waves are transverse and travel at the same speed in all directions. 4 The waves are transverse and travel more quickly in one direction than in others. student measures how far a cork moves up and down on a wave in a tank of water. ruler cork direction of wave Which quantity can he obtain from his measurement? amplitude frequency speed wavelength

5 5 5 Water waves change direction when they move from shallow water to deep water. new wave direction original wave direction deep water shallow water What is the name of this effect? diffraction 6 dispersion reflection refraction vertical stick is dipped up and down in water at P. In two seconds, three wave crests are produced on the surface of the water. Y wave crests P X Which statement is true? istance X is the amplitude of the waves. istance Y is the wavelength of the waves. Each circle represents a wavefront. The frequency of the waves is 3 Hz.

6 6 7 The drawing shows a wave. Which labelled distance is the wavelength? 8 Water waves travel more slowly in shallow water than in deep water. Which diagram shows what will happen to plane waves in deep water when they enter shallow water? deep shallow deep shallow deep shallow deep shallow MQ nswer Sheet edicated to Mohammad Irtaza Haider Zain.