Question

Find the minimum and maximum wavelengths of sound in water that is in the audible range (20 - 20000 Hz) for an average human ear. Speed of sound in water = $1450m{s}^{-}1$

• A. 100 cm, 1000 m
• B. 7.25 cm, 72.5 m
• C. 1 cm, 1 m
• D. None of the above

Answer 1

The correct option is B

7.25 cm, 72.5 m

Given, speed of sound in water, $v=1450m{s}^{-1}$

We know the speed of the sound is the distance travelled by the wave in one second.

Hence wavelength, $\lambda =\frac{v}{f}$, where f is the frequency of the wave

Wavelength for frequency 20 Hz,

${\lambda }_1=\frac{v}{f}=\frac{1450}{20}=72.5m$

Wavelength for frequency, 20000 Hz

${\lambda }_2=\frac{1450}{20000}=0.0725m$= $7.25cm$