| A | B |
|---|
| mechanical wave | a disturbance in matter that carries energy from one place to another |
| medium | the material through which a wave travels |
| crest | the highest point of a transverse wave |
| trough | the lowest point of a transverse wave |
| transverse wave | a wave that causes a medium to vibrate at right angles to the direction in which the wave travels |
| compression | an area of a longitudinal wave where the particles of the medium are close together |
| rarefaction | an area of a longitudinal wave where the particles of the medium are spread out |
| longitudinal wave | a wave in which the vibration of the medium is parallel to the direction the wave travels |
| surface wave | a wave that travels along a surface separating two media |
| periodic motion | any motion that repeats at regular time intervals |
| period | the time required for one complete cycle of a periodic motion |
| frequency | the number of complete cycles per unit time for a periodic motion |
| hertz | the unit of measure for frequency, equal for to one cycle per second |
| wavelength | the distance between a point ona wave and the same point on the next cycle of the wave |
| amplitude | the maximum displacement of a medium from a rest point |
| reflection | the interaction that occurs when a wave bounces off a surface that is cannot pass through |
| refraction | teh bending of a wave as it enters a new medium at an angle |
| diffraction | the bending of a wave as it moves around an obstacle or passes through a narrow opening |
| interference | the interaction of twp or more waves that combine in a region of overlap |
| constructive interference | the interaction among two or more waves in which displacements combine to produce a wave with a larger displacement |
| destructive interference | the interaction among two or more waves in which displacements combine to produce a wave with a smaller displacement |
| standing wave | a wave that appears tos tay in place and does not seem to move through a medium |
| node | a point on a standing wave that has no displacement from the rest position |
| antinode | a point of maximum displacement midway between two nodes in a standing wave |
| sound waves | a longitudinal wave consisting of compressions and rarefactions , which travels through a medium |
| intensity | the rate at which a wave's energy flows through a give unit of area |
| decibel | a unit that compares the intensities of different sounds |
| loudness | a physical response to the intensity of sound, modified by physical factors |
| pitch | the frequency of a sound as a listener perceives it |
| sonar | a technique for determining the distance to an object under water |
| Doppler effect | a change in sound frequency caused by motion of the sound source, motion of the listener, or both |
| resonance | the response of a standing wave to another wave of the same frequency, with dramatic increase in amplitude of the standing wave |
