Question

A hospital uses an ultrasonic scanner to locate tumours in a tissue. What is the wavelength of sound in the tissue in which the speed of sound is 1.7 km s–1 ? The operating frequency of the scanner is 4.2 MHz

Answer 1

Speed of sound in the tissue, v = 1.7 km/s = 1.7 × 103 m/s

Operating frequency of the scanner, ν = 4.2 MHz = 4.2× 106 Hz

The wavelength of sound in the tissue is given as:

$λ=\frac{v}{v}$

$=\frac{1.7×10^3}{4.2×10^6}=4.1×10^{-4}\,m$