Question

A certain ultrasound device can measure a fetal heart rate as low as 50 beats per minute. This corresponds to the surface of the heart moving at about 4.0 x 10-4 m/s. If the probe generates ultrasound that has a frequency of 2.0 MHz (1 MHz = 1 megahertz = 106 Hz), what frequency shift must the machine be able to detect

Answer 1

Answer:

The. Machine must detect a shift of

1 Hz

Explanation:

Frequency shift is given as

={ ( Vsound +V/ V sound -V) -1}f emitted

So by substitution we have

= { 1540+4E-4/1540-4E)-1) 2*10^6

= 1Hz