Production of Sound Waves and the Doppler Effect

1. Production of Sound Waves and the Doppler Effect Joe Besson Mrs. Grayot, Physics, Period VI Wave Project

2. Production of Sound Waves • Sound is caused by some vibration traveling through a medium • No sound in a vacuum

3. Characteristics of sound • Sound waves are characterized by the generic properties of waves, which are frequency, wavelength, period, amplitude, intensity, speed, and direction (sometimes speed and direction are combined as a velocity vector, or wavelength and direction are combined as a wave vector). • Transverse waves, also known as shear waves, have an additional property of polarization.

4. Characteristics of sound • Sound characteristics can depend on the type of sound waves (longitudinal versus transverse) as well as on the physical properties of the transmission medium. • Whenever the pitch of the sound wave is affected by some kind of change, the distance between the sound wave maxima also changes, resulting in a change of frequency. • When the loudness of a sound wave changes, so does the amount of compression in airwave that is travelling through it, which in turn can be defined as amplitude.

5. Doppler Effect • named after Austrian physicist Christian Doppler • It is commonly heard when a vehicle sounding a siren approaches, passes and recedes from an observer

6. Doppler Effect explained • observed frequency f and emitted frequency f0 is the velocity of waves in the medium, the velocity of the source relative to the medium, the velocity of the receiver relative to the medium

7. http://www.kettering.edu/~drussell/Demos/doppler/doppler.htmlhttp://www.kettering.edu/~drussell/Demos/doppler/doppler.html http://www.lon-capa.org/~mmp/applist/doppler/d.htm