Medical equipment uses ultrasound to process images using resonance the doppler effect constructive interference destructive interference

The medical equipment used for ultrasound imaging is based on Doppler's effect.

The ultrasound imaging process uses high frequency radio waves to view inside images like tendons,muscles,joints,blood vessels etc.

In this process the transmitted pulse produces a Doppler's shift when it interacts with the moving reflector. Here we have to consider the moving reflector as the moving source.The moving reflector will produce an echo which will be received by the transducer.The transducer acts as stationary observer.

The whole process can be explained as below-

1-The ultrasound machine transmits the high frequency signal to the body through a prove.The sound will be reflected by the boundary of tissue and received by the probe.Some sound waves penetrate more into inside part of the body.

2-The received reflected sound will be allowed to enter into the machine which calculates the distance between various tissue and forms an image based on Doppler's shift.

Hence the correct answer is Doppler's effect.

i think it's 35 meters