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 kms^(-1)` ? The operating frequency of the scanner is 4.2 MHz.

Explanation

Given , `v = 1.7 xx 10^(3) ms^(-1), f = 4.2 xx 10^(6) Hz`.
Wavelength of sound in the tissue `= ( v)/( f)= ( 1.7 xx 10^(3))/( 4.2 xx 10^(6)) =0.405 xx 10^(-3) = 4.05 xx 10^(-4) m`
Note `:` The product of number of waves and wavelength of sound in the tissue determines the length of the tumour or any foreign bodies.