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A person deep inside water cannot hear sound produced in air. Why? |
Answer» As speed of sound in water is roughly four times the speed of sound in air, therefore μ = \(\frac {sin \,i}{sin\, r}=\frac{v_a}{v_w}\) = \(\frac{1}{4}\) = 0.25 For refraction, rmax = 90º ∴ (sin i)max =0.25 ∴ imax ≈ 14º . That is why most of sound produced in air and falling at ∠i>14º gets reflected in air and person deep inside water cannot hear the sound. |
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