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


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