Understanding the Doppler Effect

What does the Doppler effect describe?

• The reflection of waves from surfaces

• The change in wave amplitude over distance

• The change in wave speed due to motion

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

If a fire truck is moving towards you, how will the sound of its siren change?

• It will become quieter

• It will have a lower pitch

• It will sound the same

• It will have a higher pitch

What happens to the sound waves when a vehicle moves away from you after passing by?

• The waves increase in frequency

• The waves decrease in frequency

• The waves reflect back

• The waves stop

What does a higher frequency of sound waves indicate when a car approaches you?

• The car is stationary

• The car is speeding up

• The car is slowing down

• The car is moving towards you

What is the audible effect observed when a source of sound moves away from an observer?

• The sound becomes distorted

• The pitch of the sound decreases

• The sound becomes louder

• The pitch of the sound increases

How does the Doppler effect apply to light waves from a star moving towards Earth?

• The light appears redder

• The light appears bluer

• The light appears unchanged

• The light appears greener

What is redshift in the context of the Doppler effect?

• A shift towards infrared light

• A shift towards ultraviolet light

• A shift towards lower frequencies of light

• A shift towards higher frequencies of light

What does the change in color of light from stars due to the Doppler effect indicate?

• The motion of the star relative to Earth

• The age of the star

• The size of the star

• The chemical composition of the star

How do astronomers use the Doppler effect?

• To measure the temperature of stars

• To determine if celestial bodies are moving towards or away from Earth

• To determine the texture of celestial bodies

• To find the distance of stars from Earth