Two speakers are driven by the same oscillator with frequency of 200 Hz. They are located 4 m part on a vertical pole. A man walks straight towards the lower speaker in a direction perpendicular to the pole, as shown in figure. (i) How many times will he hear a minimum in sound intensity, and (ii) how far is he from the pole and at these moments ? Take the speed of sound to be 330 m/s, and ignore any sound reflections coming off the ground.
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Explanation

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