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.
Given:
Speed of sound in the tissue, vs = 1.7 Km/s or 1.7× 103 ms-1
Operating frequency of the scanner, v = 4.2 MHz or 4.2× 106Hz
The wavelength of the sound in the tissue is given as,
λ = vs/v
λ = 1700ms-1/ 4.2× 106s-1
λ = 4.1× 10-4m