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प्रश्न
What should be the minimum distance between source and reflector in water so that echo is heard distinctly?
(The speed of sound in water = 1400 m s-1)
उत्तर
t = 0.1 sec,
v = 1400 m/s
t = `(2d)/v`
Or d = `(tv)/2`
= `(0.1 xx 1400)/2`
= 70 m
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