Question
A vehicle moving toward a stationary observer emits a sound. A graph shows the frequency heard by the observer over time.
Why does the observed frequency change as the vehicle approaches and passes the observer? (Hint: Unit 5 Lesson 4)
(2 points)
Responses
The sound's amplitude goes up and down.
The sound's amplitude goes up and down.
The motion of the vehicle causes the speed of the sound wave to change which in turn affects frequency.
The motion of the vehicle causes the speed of the sound wave to change which in turn affects frequency.
The frequency heard by the observer increases as the vehicle approaches and decreases as it moves away due to the Doppler effect.
The frequency heard by the observer increases as the vehicle approaches and decreases as it moves away due to the Doppler effect.
The sound the vehicle makes changes as it moves along.
The sound the vehicle makes changes as it moves along.
Why does the observed frequency change as the vehicle approaches and passes the observer? (Hint: Unit 5 Lesson 4)
(2 points)
Responses
The sound's amplitude goes up and down.
The sound's amplitude goes up and down.
The motion of the vehicle causes the speed of the sound wave to change which in turn affects frequency.
The motion of the vehicle causes the speed of the sound wave to change which in turn affects frequency.
The frequency heard by the observer increases as the vehicle approaches and decreases as it moves away due to the Doppler effect.
The frequency heard by the observer increases as the vehicle approaches and decreases as it moves away due to the Doppler effect.
The sound the vehicle makes changes as it moves along.
The sound the vehicle makes changes as it moves along.
Answers
GPT-4o mini
The best response to explain why the observed frequency changes as the vehicle approaches and passes the observer is:
**The frequency heard by the observer increases as the vehicle approaches and decreases as it moves away due to the Doppler effect.**
This is because the Doppler effect describes the change in frequency (and wavelength) of a wave in relation to an observer moving relative to the source of the wave. As the vehicle approaches the observer, the sound waves are compressed, resulting in a higher frequency. Conversely, as the vehicle moves away, the sound waves are stretched, leading to a lower frequency.
**The frequency heard by the observer increases as the vehicle approaches and decreases as it moves away due to the Doppler effect.**
This is because the Doppler effect describes the change in frequency (and wavelength) of a wave in relation to an observer moving relative to the source of the wave. As the vehicle approaches the observer, the sound waves are compressed, resulting in a higher frequency. Conversely, as the vehicle moves away, the sound waves are stretched, leading to a lower frequency.