Doppler effect

Front

What is the Doppler effect?

Back

The Doppler effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source.

Front

How does the Doppler effect affect sound waves when the source is moving towards an observer?

Back

When the source of sound waves is moving towards an observer, the frequency of the sound waves increases, resulting in a higher pitch.

Front

How does the Doppler effect affect sound waves when the source is moving away from an observer?

Back

When the source of sound waves is moving away from an observer, the frequency of the sound waves decreases, resulting in a lower pitch.

Front

What happens to the sound of an ambulance siren as it approaches you?

Back

As an ambulance siren approaches, the sound becomes louder and the pitch increases due to the Doppler effect.

Front

What happens to the sound of an ambulance siren as it moves away from you?

Back

As an ambulance siren moves away, the sound becomes quieter and the pitch decreases due to the Doppler effect.

Front

What is a sound wave?

Back

A sound wave is a wave of compression and rarefaction that propagates through an elastic medium, such as air.

Front

What is the relationship between wave frequency and pitch?

Back

Higher wave frequencies correspond to higher pitches, while lower wave frequencies correspond to lower pitches.

Front

What is the significance of the observer's motion in the Doppler effect?

Back

The motion of the observer relative to the wave source affects the perceived frequency and pitch of the sound.

Front

What is the formula for calculating the observed frequency in the Doppler effect?

Back

The observed frequency (f') can be calculated using the formula: f' = f (v + vo) / (v + vs), where f is the source frequency, v is the speed of sound, vo is the speed of the observer, and vs is the speed of the source.

Front

What is the speed of sound in air at room temperature?

Back

The speed of sound in air at room temperature (20°C) is approximately 343 meters per second.