The correct answer to the question above is The third Option: C; ultrasound imaging of the liver. The ultrasound imaging of the liver is definitely not an application of Doppler technology.
Liver ultrasound is not an application of the Doppler effect. The use of ultrasound is more common in medicine, for example, during pregnancy.
Another application in medicine is with the movement of blood. It is a flowmeter which allows the blood flow to be discovered through the Doppler effect, since a sound wave affects the red blood cells that are in motion inside the vessel and collect the echo signal.
The black squirrel has zero kinetic energy (if it's not moving) and lower gravitational potential energy than the red squirrel or zero gravitational potential energy if the ground is assumed to be zero gravitational potential line.
