# Doppler Effect with heart motion

1. Dec 9, 2008

### rpcarroll

1. The problem statement, all variables and given/known data
Suppose a heart's ventricular wall moves in simple harmonic motion with amplitude 1.8mm and a frequency of 115 per minute. (a) Given a motion detector in contact with the chest produces sound at 2,000,000Hz which travels through tissue at 1.50 km/s. Find the maximum linear speed of the heart wall. (b) Find maximum frequency at which the sound arrvies at the heart. (c) Find the maximum frequency which at which sound is recieved by the motion detector.

2. Relevant equations
f'=fo((Vo+Vmax)/Vo)

3. The attempt at a solution
(a) 115=2,000,000((1.5+Vmax)/1.5)
Vmax=1.5
I am struggling with some of the concepts and where different terms can be applied, any suggestions? Do I need to convert any units?

2. Dec 9, 2008

### turin

The wording of (a) is quite confusing, but I think that you don't need the info about the motion detector. (b) is ambiguous, but I would imagine you need to take into acount the doppler effect. You will have to think about (c) a bit.

I don't think so.