Physics - Sound Wave Question with Solution | TestHub

Speed of the wave$v=\text{1.7} \mathrm{km} {\mathrm{s}}^{-1} =\text{1.7}\times {10}^3 \mathrm{m} {\mathrm{s}}^{-1}$
Operating frequency of the scanner$f =\text{ 4.2} \mathrm{MHz} = 4.2 \times {10}^6 \mathrm{Hz}$

∴ Wavelength of sound in the tissue,
$\lambda =\frac{v}{f}=\frac{\text{1.7}\times 10^3}{\text{4.2}\times 10^6}$

$\approx \text{4.1}\times {10}^{-4} \mathrm{m}$

Note:Ultrasonic waves are the sound waves of frequencies higher than audible range. They travel through human tissue differently depending upon the density of the soft or hard tissues.