Chapter 12

the height of a wave, measured from the center line of a wave to the top of a peak.

the study of crystal structures by means of X-Ray diffraction.

when waves encounter corners or obstructions and bend and spread out a s a result.

the change of pitch perceived when the pitch is produced by a moving object and the object passes by the observer. the pitch is higher than normal as the moving object approaches because the motion compresses the wave length of the sound waves, and lower than normal after the object passes because the motion stretches the out the wavelength of the sound waves.

the process used by bats, dolphins, and other some animals to navigate and hunt by means of emitting sounds and interpreting the echoes that come back.

an oscillating system, the number of cycles completed per second.

a term that describes a ray or wave as it approaches the boundary of a new medium, where it reflects and/or refracts.

a wave with the characteristic that the oscillation producing the wave is moving parallel to the direction in which the wave propagates.

any wave requiring a medium in which to propagate; all waves except electromagnetic waves.

matter of some kind through which the energy of mechanical waves can propagate.

a line perpendicular to the boundary between two media, used as a reference for measuring angles involved in wave reflection and referaction.

continuous, periodic moment back and forth or up and down.

the length of time required for an osculating system to complete one full cycle of its oscillation.

when a wave bounces of the boundary between two media, obeying the law of reflection in the process.

when a wave passes through a boundary separating two media, changing velocity and direction in the process.

a technology in which echoes of sound waves are used to locate objects under water.

a wave on water formed by the wind.

a wave with the characteristic that the oscillation producing the wave is perpendicular to the direction in which the wave is propagating.

any sound wave with a frequency higher than about 20 kHz, the upper limit of human hearing.

a disturbance in place and time that carries energy from one place to another.