A scuba diver is deep inside the sea when a source produces loud sound in air which can be heard from far distance. Even though the speed of sound is greater in water, reason out a possibility for why he is not able to hear that sound ?

A scuba diver is deep inside the sea when a source produces loud sound

1.	A scuba diver is deep inside the sea when a source produces loud sound in air which can be heard from far distance. Even though the speed of sound is greater in water, reason out a possibility for why he is not able to hear that sound ?
Answer» Solution :The speed of sound in water is four times the speed of sound in air. Now, from Snell's LAW of refraction, `mu = (sin i)/(sin r) = ("Speed of sound in air")/("Speed of sound in water") = (1)/(4) = 0.25` For REFREACTION, `r_(MAX) = 90^(@)`. So, `(sin i)_(max) = 0.25 or i_(max) = 14^(@)`. As a result, most of the sound generated by the source in air and incident at ANGLE `i gt 14^(@)` gets reflected back in air and only a very small amount is refracted into water. So, the SCUBA diver deep inside the sea will not be able to hear even a loud sound.