Sound and the Doppler Effect

When a siren is approaching you, how does the observed pitch of the siren compare to what you hear after it moves past you?

• The siren sounds the same throughout

• The pitch is higher before it moves past

• The pitch gets lower and lower until it reaches me.

• The siren's pitch sounds lower after it moves past me.

• The pitch gets higher after it moves past me.

Tags

NGSS.HS-PS4-1

Which is the most accurate definition of the Doppler Effect?

• It's the way in which sound gets louder and louder as the object gets closer to the observer.

• It's the apparent change in the amplitude of a wave caused by relative motion between the source of the wave and the observer.

• It's the apparent change in the frequency of a wave caused by relative motion between the source of the wave and the observer.

• It's the apparent change in the speed of a wave caused by relative motion between the source of the wave and the observer.

Tags

NGSS.HS-PS4-1

When a siren is approaching you, how does the wavelength of the waves reaching you compare to the wavelength that the siren emits?

• The waves of the siren are compressed, so the wavelength of the waves reaching you is shorter than the wavelength that the siren emits.

• The waves of the siren are compressed, so the wavelength of the waves reaching you is longer than the wavelength that the siren emits.

• The waves of the siren are stretched, so the wavelength of the waves reaching you is shorter than the wavelength that the siren emits.

• The waves of the siren are stretched, so the wavelength of the waves reaching you is longer than the wavelength that the siren emits.

Tags

NGSS.HS-PS4-1

What kinds of waves experience the Doppler Effect?

• Sound

• Light

• Water

• All of these

Tags

NGSS.HS-PS4-3

NGSS.HS-PS4-5

Four students are asked: Why are you able to observe the Doppler Effect with sound waves on Earth but not light waves?

Which student has the most accurate answer?

• Dave: Because light waves move so quickly, the Doppler Effect doesn't apply to them.

• Steve: The Doppler Effect only works on a limited range of frequencies.

• Jess: The Doppler Effect works on light waves, but it's moving too fast for us to observe the differences in frequencies.

• Jenn: The Doppler Effect is only detectable when the source or observer are moving toward or away from each other at a velocity that is a measurable fraction of the wave being emitted.

Tags

NGSS.HS-PS4-1

When stars are moving away from a telescope, what shade do they appear to be compared to the normal light they emit?

• Redder

• Bluer

• Purpler

• Whiter

Tags

NGSS.HS-ESS1-2

NGSS.HS-PS4-1

What is it called when a galaxy is moving toward us at a very high speed?

• Redshift

• Blueshift

• Nightshift

• Rightshift

Which of the following is NOT an everyday application of the Doppler Effect mentioned in the video?

• Weather forecasts

• Police radar detectors

• Hand sanitation

Tags

NGSS.HS-PS4-1

NGSS.HS-PS4-5

Which of the following variables is NOT needed in order to determine the frequency of the wave that will be observed?

• Velocity of the source

• Velocity of the observer

• Velocity of the wave through the medium

• Frequency of the wave the source is emitting

• The amplitude of the wave

Tags

NGSS.HS-PS4-1

What is created when an object travels faster than the speed of sound?

• Sonic boom

• Flash of light

• Babies

• The Doppler Effect

Tags

NGSS.HS-PS4-1