Answer:
Step-by-step explanation:
) Doppler effect deals with change in the frequency of sound or light that takes place in case there is relative motion between source of sound and listener of sound.
Police uses a device called police radar gun to check the speed of oncoming vehicles. It uses electromagnetic signal for this purpose. Change in the frequency of reflected signal tells about the speed of the object from which it was reflected.
Apart from it meteorologists also use a device based on this effect to know and track the storms . It not only tracks the storms but also tells about the speed of it.
Doctors too use devices based on this effect to diagnose heart problems.
A doppler ultrasound is used to know the speed of flow of blood in artery or blood vessel.