Chapter 7 Flashcards
periodic back-and-forth motion that transmits energy
wave
substance through which a wave travels
medium
high point of a wave train
crest
low point of a wave train
trough
waves in which particles of the transmitting medium oscillate at right angles
transverse wave
waves in which particles of the transmitting medium oscillate in the direction of wave motion
longitudinal wave
portion of the longitudinal wave that is spread out
rarefaction pulse
portion of the wave that is squeezed together
compression pulse
length of a single wave
wavelength
maximum distance that particles are displaced by a wave
amplitude
inverse of a period; number of waves that pass a given point per unit time
frequency
SI unit of frequency
hertz
time needed for one wave cycle to pass
period
what is directly proportional to both wavelength and frequency
speed
change in the course of a wave as a result with an object or boundary
reflection
what does the law of reflection state
angle of incidence equals angle of reflection
spreading out of a wave after it passes through a narrow opening
diffraction
bending of the path of a wave as a result in change of speed
refraction
diffraction causes the wave to spread out evenly when the opening is roughly equal to ___ ___
one wavelength
refracted waves always bend toward what?
the medium that slows it down
temperature at which sound travels
331 m/s
occurs when two or more waves meet
interference
when a crest and trough with the same amplitude meet
complete destructive interference
when a crest meets a trough
destructive interference
when two crests or troughs meet
constructive interference
vibrations traveling through a medium in the form of longitudinal pressure waves
sound
in order for sound to travel, it needs a ___
medium
strength of a sound wave
intensity
effect of intensity on the way the human ear perceives sound
loudness
used to measure sound intensity level
decibel
effect of frequency on the way the human ear perceives sound
pitch
sound that can be heard
audible
pitches below the audible range
infrasonic sounds
sounds with pitches above the audible range
ultrasonic sound
change in frequency caused by an object’s motion
Doppler effect
main factor affecting the speed of sound
temperature
speeds above the speed of sound
supersonic
speeds below the speed of sound
subsonic
noise a shock wave produces
sonic boom
violent compression pulse
shock wave
multiple reflections causing a persistence of sound
reverberation
sound heard distinctly after being reflected from an object
echo
developed to locate enemy submarines
sonar
process of dissipating the energy of sound waves
absorption
study of sound
acoustics
series of organised sound waves that have deliberately been arranged
music
random sound with no intended pattern
noise
difference in pitch between two notes that has twice the frequency of the first note
octave
two notes interfering harmoniously
consonance
two notes interfering disagreeably
dissonance
distance between two musical notes
interval
a burst of loud sound pertaining to music
beat
the low, dominant sound an instrument plays
fundamental
sounds other than the fundamental an instrument plays
overtones
The frequency relationships between the fundamental and overtones
harmonic series
distinct sound of an instrument
timbre
set of frequencies at which an object vibrates
natural frequencies
when two frequencies are the same or nearly the same
resonance
an opening to a hollow body
resonator