Katie, why does the ambulance siren sound different as it drives further away to when it is stationary?
Well Matt...
It is due to the Doppler Effect. As the ambulance approaches this man, the wavelength is shorter, making the siren higher pitched.
NEE-NORR NEE-NORR
Wavelength
Katie and Matt are sitting outside playing cards, and a high pitched ambulance siren comes towards them.
Whereas when the ambulance moves away from the man, the wavelength is longer, making it a lower frequency.
Wavelength
NEEEEE-NORRRRR NEEEEEE-NORRRRR
The ambulance siren gets lower in pitch. Matt asks Katie a question.
Katie shows Matt a diagram to explain the doppler effect.
NEEEEEE-NORRRRR NEEEEEE-NORRRRR
I win!
Katie explains what happens when the ambulance drives away.
Matt thanks Katie for helping him understand the Doppler Effect.
Wow, that's so cool! Thanks!
The ambulance siren gets lower as it drives away.