A hospital uses an ultrasonic scanner to locate tumours in a tissue. What is the wavelength of sound

Question

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

Professor PC Thomas Classes · Answer

$\lambda = v / f = 1700 / (4.2 	imes 10^6) = 4.047 	imes 10^{-4}$ m, which is approximately $4.05 	imes 10^{-4}$ m.