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Question:

The Dobbler Effect, using ultrasonic waves of frequency of 2.25 *10^6 Hz is used to monitor the heartbeat of a fetus. A beat frequency of 500Hz is observed. Assuming the speed of sound is 1.54 *10^3 m/s, calculate the maximum velocity of the surface of the beating heart.

Equations:

Only one relevant equation:

f'=f((Vsound (+ or -) Vobserver)/(Vsound (- or t) Vsource))

Attempt

I know that the answer is .171m/s. I also know that in this questions, you have to use the above formula two times (double dobbler effect) to get the answer. If anyone can help me, I would really appreciate. I have pretty much tried plugging every number into the formula above, but everytime i do it, i never get .171m/s as my final answer! Maybe I am confusing whether the heart is the source of the observer. Please help!! Thanks

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# Homework Help: Dobbler Effect Question

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