Unit 7 Flashcards
Doppler Effect
the change in the observed frequency of a wave because of the motion of the source or the observer toward or away from the other; the frequency increases when the source and observer approach each other and decreases when they move apart
Acoustics
the science and study of sound, including its production, propagation, and effects; also, qualities determining the ability of an enclosure
Amplitude
\AM-pluh-tood\
in a wave, the maximum displacement of a wave from its rest position—that is, distance from rest to crest or rest to trough
Compression
in a medium through which sound is passing, a high-pressure region of a sound wave
Constructive Interference
effect that occurs when two waves with synchronized crests and troughs meet
Destructive Interference
effect that occurs when two waves with crests and troughs that are out of phase meet, effectively canceling each other out to zero amplitude at a point
Frequency
the number of waves that pass through a point during a specific amount of time
Hertz
the SI-derived unit of frequency in the metric system; it is a unit equal to one cycle per second
Longitudinal Waves
for mechanical waves, waves in which the movement in the medium is parallel to the direction the wave is traveling
Medium
\MEE-dee-uhm\
substance that is the means of transmission of a force or effect; in the case of waves, air, water, other gases, and solid earth are all mediums through which different types of waves can travel
Period
the time for a wave, or one cycle of a repeating wave, to pass a location
Pitch
in music and acoustics, refers to the frequency of a given tone in that pitch is the perceived highness or lowness of a sound—high frequency sound waves are associated with high pitch, and low frequency sound waves are associated with low pitch; frequency can be physically measured, whereas pitch is perceived, therefore pitch is not synonymous with frequency
Rarefaction
in a medium through which sound is passing, a low-pressure region of a sound wave
Sonic Boom
\SAH-nik\
piled-up sound waves manifested as a violent shock wave propagating behind an object that is traveling at supersonic speed (faster than the speed of sound); the object catches up with its own noise and at higher speeds forces the sound ahead of itself faster than the noise would normally go, creating the piled-up and booming sound effect
Speed
the rate at which an object changes position
Standing Wave
a pattern formed when two waves of the same amplitude and frequency move simultaneously through a medium in opposite directions (the wave appears to oscillate but not propagate); also stationary wave
Transverse Waves
for mechanical waves, waves in which the movement in the medium is perpendicular to the direction the wave is traveling
Traveling Wave
a wave that continuously carries energy away from its source
Velocity
\veh-LAH-suh-tee\
the rate at which an object changes position when traveling in a certain direction, expressed as a rate: the distance an object traveled from one position to the next divided by the time it took to travel the distance
Wavelength
distance from one point on a wave to the next same point on a wave (for example, distance from crest to crest or trough to trough); distance of one wave cycle
