Does a police cars frequency become higher moving toward a stationary observer or away from? I am confused as to how we hear the frequency anyways..
The frequency of a police car's siren does not change as it moves towards or away from a stationary observer. The frequency remains constant. However, the perception of the frequency does change due to the Doppler effect.
The Doppler effect is the shift in frequency or pitch that occurs when a sound source moves relative to an observer. When the police car is moving towards the observer, the sound waves produced by the siren are compressed, resulting in a higher perceived frequency or pitch. This is known as the "Doppler shift to higher frequency." Conversely, when the police car moves away from the observer, the sound waves are stretched, resulting in a lower perceived frequency or pitch. This is known as the "Doppler shift to lower frequency."
To understand how we hear the frequency, we need to consider how sound travels. Sound is a mechanical wave that travels through a medium, usually air. When the police car's siren is turned on, it emits sound waves that travel in all directions. As these waves reach our ears, they cause the eardrum to vibrate, and our brain interprets these vibrations as sound.
Now, to answer your question about how we hear the frequency, our ears do not directly detect the frequency itself. Instead, they detect the vibrations caused by sound waves. Our brain then processes these vibrations and interprets them as different frequencies. So, we perceive the frequency as the pitch of the sound.
In summary, the frequency of a police car's siren does not change as it moves towards or away from a stationary observer. However, due to the Doppler effect, the perception of the frequency changes. Our ears detect the vibrations caused by the sound waves, and our brain interprets these vibrations as different frequencies or pitches.