1. Which Way Did That Thing Go?
Sound & Doppler Effect

2. Sound Facts Sound is transmitted as a LONGITUDINAL wave.
Sound is a mechanical wave so it requires A MEDIUM TO BE TRANSMITTED.
Speed of sound in…
air: 331 m/s
sea water: 1435 m/s
steel: 5100 m/s
Amplitude of a sound wave is synonymous with VOLUME, LOUDNESS, INTENSITY

5. Phenomenon #5 – Doppler Effect
A source sends out waves in all directions with the same frequency and wavelength.
How the wave is perceived by an observer depends on RELATIVE MOTION of the source and/or observer.

7. Phenomenon #5 – Doppler Effect
Same frame of reference (no relative motion)
FREQ. OBSERVED (FOBS) = SOURCE FREQ.(FSOURCE) A B

8. Phenomenon #5 – Doppler Effect
Getting closer together – FOBS > FSOURCE
… at increasing speed – GETTING HIGHER
… at decreasing speed – GETTING LOWER
Getting farther apart – FOBS < FSOURCE
… at increasing speed – GETTING LOWER
… at decreasing speed – GETTING HIGER B A

9. Doppler Constant Speed Doppler Changing Speed
Doppler Sonic Boom

12. End of PRACTICE