The Doppler Shift of Ultrasonic Waves Can Measure the Speed

Multiple Choice

The Doppler shift of ultrasonic waves can measure the speed of blood in an artery.If the frequency of the stationary source is 100 kHz and the reflected sound has a Doppler shift of 300 Hz,what is the blood flow speed? (The speed of sound inside the body is 1500 m/s. )

A) 1.0 m/s
B) 1.5 m/s
C) 2.2 m/s
D) 3.3 m/s