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A man fires a gun and hears its echo after 5 s. The man then moves 310 m towards the hill and fires his gun again. If he hears the echo after 3 s, calculate the speed of sound. |
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Answer» Distance (d) = velocity (v) × time (t) Distance travelled by sound when gun fires first time, 2d = v × 5 ……(1) Distance travelled by sound when gun fires second time, 2d – 620 = v × 3 …….(2) Rewriting equation (2) as, 2d = (v × 3) + 620 ………(3) Equating (1) and (3), 5v = 3v + 620 2v = 620 . Velocity of sound, v = 310 m s-1 |
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