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

Explanation

Speed of sound, `upsilon = 1.7 kms^(-1)`
`= 1.7 xx 10^(3) ms^(-1)`
Frequency of the scanner = 4.2 MHz
`= 4.2 xx 10^(6) Hz`
Wavelength, `lambda = (upsilon)/(v) = (1.7 xx 10^(3))/(4.2 xx 10^(6)) = 4.05 xx 10^(-4)` m
`= 4.05 xx 10^(-4)` m.