Doppler Effect

What is the Doppler Effect?

• The bending of waves around obstacles.

• The change in color of light due to motion.

• The interference of waves leads to increased amplitude.

• The change in frequency of a wave due to the motion of the source or the observer.

What happens to the frequency of sound waves when a sound source moves toward an observer?

• The frequency increases.

• The frequency decreases.

• The frequency remains the same.

• It depends on the initial frequency of the sound.

Tags

NGSS.HS-PS4-1

What happens to the frequency of sound waves when a sound source moves away from an observer?

• The frequency increases.

• The frequency decreases.

• The frequency remains the same.

• It depends on the initial frequency of the sound.

Tags

NGSS.HS-PS4-1

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

• The pitch increases.

• The pitch decreases.

• The pitch remains the same.

• The pitch becomes indistinguishable.

Tags

NGSS.HS-PS4-1

What happens to the wavelength as the source moves towards the observer?

• The wavelength increases.

• The wavelength decreases.

• The wavelength remains the same.

• It does not have enough information therefore it cannot be determined.

Tags

NGSS.HS-PS4-1

What happens to the frequency as the observer moves towards the source?

• The frequency increases.

• The frequency decreases.

• The frequency remains the same.

• It depends on the initial frequency of the sound.

Tags

NGSS.HS-PS4-1

When an ambulance moves towards you, how does the siren sound?

• No sound

• No change

• Low pitched

• High pitched

Tags

NGSS.HS-PS4-1

When an ambulance moves away from you, how does its siren sound?

• No sound

• No change

• Low pitched

• High pitched

Tags

NGSS.HS-PS4-1

The Doppler Effect produces apparent changes in

• Amplitude

• Frequency

• Phase

• All of the above

Tags

NGSS.HS-PS4-1

An observer is moving towards a stationary source of frequency 250 Hz with a velocity of 40 m/s. If the velocity of sound is 330 m/s, the apparent frequency heard by the observer will be

• 230 Hz

• 280 Hz

• 300 Hz

• 320 Hz

Tags

NGSS.HS-PS4-1