Question

A scientist uses an ultrasound device mounted to a vehicle to measure fluid flow underground. The device makes use of the Doppler effect to track fluid movement in the water table. Which of the following scenarios is most likely to produce a readable Doppler shift?

I. The fluid is flowing at a velocity twice that of the sound-emitting device, in the same direction as the device is moving.

II. The fluid is flowing at the same velocity and in the same direction as the sound-emitting device is moving.

III. The fluid is not moving at all.

Answer 1

The scenario with the fluid flowing at a velocity twice that of the sound-emitting device, in the same direction as the device is moving, is most likely to produce a readable Doppler shift.

Step-by-step explanation:

The scenario that is most likely to produce a readable Doppler shift is scenario I, where the fluid is flowing at a velocity twice that of the sound-emitting device, in the same direction as the device is moving. The Doppler effect occurs when there is relative motion between the observer (the sound-emitting device) and the source (the fluid). In this scenario, the relative motion enhances the Doppler effect, resulting in a noticeable shift in the frequency of the ultrasound waves reflected from the fluid.