Question

To clearly see an image, the wavelength used must be at most 1/4 of the size of the object that is to be imaged. what frequency is needed to image a fetus at 8 weeks of gestation that is 1.6 cm long?

use 1500 m/s as the speed of sound in tissue.

Answer 1

The wavelength must be
λ = (1/4) (1.6 cm) = 0.4 cm or 0.004 m
The frequency can be solved using the formula
f = v / λ
we are given with
v = 1500 m/s

Substituting the values
f = 1500 m/s / 0.004 m
f = 375000 /s or 375 kHz