試題詳解

54. A doppler flow meter transmit ultrasound of 10 MHz to measure the blood flow. If the reflected sound of 9.9 MHz is recorded by the same probe, find the speed of the blood flow. (sound speed in the tissue is 1500 m/s)
(A) 5.5 m/s
(B) 6.5 m/s
(C) 7.5 m/s
(D) 8.5 m/s
(E) 9.5 m/s