A sound wave travelling in water has wavelength 0.4 m. Is this wave audible in air? (The speed of sound in water = 1400 ms^-1).

Given,

wavelength = 0.4 m

speed of sound in water = 1400 m s^-1

As we know,

frequency of wave = $\dfrac{\text{Speed}}{\text{Wavelength}}$

Substituting the values we get,

$\text{frequency of wave} = \dfrac{1400}{0.4} \\[0.5em] \text{frequency of wave} = 3500 \text{ Hz} = 3.5 \text{ kHz} \\[0.5em]$

Hence, we get the frequency of wave = 3500 Hz and this lies in the audible range of frequency (i.e., 20 Hz to 20,000 Hz), hence it is audible.