| A | B |
|---|
| vibrating objects | produce sound waves |
| crest | highest point of a wave |
| amplitude | the total height of a wave |
| wavelength | the distance between two indentical parts of two waves |
| interference | when two waves approach each other from opposite directions |
| constructive interference | when the crests and troughs line up and create a larger wave |
| destructive interference | when a crest lines up with a trough creating a smaller wave |
| sound waves are | longitudinal and mechanical |
| sounds wave need | a medium - cannot travel though a vacuum |
| sound travels | faster through a solid, slower through air |
| natural frequency | the frequency at which an object naturally vibrates |
| resonance | when an object is made to vibrate at it's natural frequency |
| beats result from | interference of two similar frequencies occuring at the same time |
| Hertz | unit of frequency - waves per second - 2 waves in one second, 2 hertz |
| transverse wave | energy moves perpendicular to the direction of the wave |
| fixed reflection | the wave will be upside down - opposite |
| free end reflection | wave will come back right side up - exact same wave |
| compressions | areas of a lolongitudinal wave where the medium is compressed |
| doppler | higer pitch when moving toward you - lower pitch when moving away |
| node | area of no vibration |
| antinode | area of greatest vibration |
| sonic boom | sound made when something goes faster than the speed of sound |
| refraction | wave bending when going from one medium to another |
| diffraction | wave wrappin around a barrier |
| standing wave | repeating pattern of waves that have points of no movement and points of maxium movement |
| pitch | the observers interpretation of frequency |
| human hearing range | 20 to 20000 hertz |
| utrasonic | sound frequencies above human hearing |
| infrasonic | sound frequencies below human hearing |
| decibel | used to measure the loudness of sound |
| subsonic | moving slower than speed of sound |
| supersonic | moving faster than speed of sound |
