Summary
- Drawing sound waves
- One dimensional technique
- Sound waves can be drawn as a pressure-time or pressure-distance graph.
- Sound waves are still longitudinal waves despite the fact that this technique makes them look like transverse waves.
- Two dimensional technique
- Sound waves can be drawn as wavefronts.
- Wavefronts are the locus of all points in space with the same phase.
- The wavefronts from a stationary, point source of sound are concentric circles.
- The wavefronts from a moving, point source of sound are circles that are positioned closer together in front of the source and farther apart behind the source.
- dopplershock.pdf
- The Doppler effect…
- is the apparent change in the frequency of a wave caused by relative motion between the source of the wave and the observer.
- applies to all types of waves.
- increases the frequency of a wave (raises the pitch of a sound wave) when the source moves toward the observer.
- decreases the frequency of a wave (lowers the pitch of a sound wave) when the source moves away from the observer.
