Question

Which of the following is an example of the doppler effect

Answer 1

The siren of a police car sounds different when the car is coming toward you than it does when it passes.

Step-by-step explanation:

The Doppler effect refers to the apparent change in the frequency of a sound wave when the distance between the source of the sound and the listener changes at a rapid pace. When a race car zooms past you, the change in the sound is very dramatic because of the rapid change in the distance between you and the source of the sound.

PF

Answer 2

"A train blows its horn as it travels towards you, and you perceive the pitch of the horn to increase" is an example of the Doppler effect.

Step-by-step explanation:

Christian Doppler, physicist from Austria was the first to launch "Doppler effect" in 1842. It is variation in wave frequency in the response to a body or object which move nearby the waves sources. The phenomenon is observed in sound, light and other waves.

As the source of the wave moves closer to the listener the frequency of the wave increases in sound waves while the sound starts to faint when the source moves away.

Doppler effect is applicable in a mechanism called red shift or blue change in order to calculate the velocity at which stars and galaxies approach or recede from us.