Physical Science Chapter 7 Flashcards
a back and forth motion that transmits energy
wave
a substance through which a wave transfers its energy
medium (media is plural)
a portion of a wave that only has a crest or only a trough
wave pulse
a wave in which particles of the transmitting medium oscillate at right angles to the direction of wave travel
transverse wave
a series of waves
wave train
high point on a wave
crest
low point on a wave
trough
a wave in which particles of the transmitting medium oscillate in the direction of wave motion
longitudinal wave
the pulse of a longitudinal wave in which particles of the transmitting medium are squeezed together
compression pulse
the pulse of a longitudinal wave in which particles of the transmitting medium are spread out
rarefaction pulse
a spring that is stretched or compressed will produce a restorative force that resists the stretching or compression
Hooke’s law
an oscillation caused by a restorative force that is proportional to the displacement from equilibrium
simple harmonic motion
the length of a single wave
wavelength
the maximum distance that particles are displaced by a wave
amplitude
the number of waves that pass a given point per unit time
frequency
the time needed for one cycle of a repeating process like the swing of a pendulum or the passing of a wave
period
the rate at which a wave travels through a medium
speed
a change in the course of a wave as a result of a collision with an object or boundary
reflection
waves that strike the boundary
incident waves
waves that “bounce” off the boundary
reflected waves
states that the angle of incidence equals the angle of reflection
law of reflection
the bending of a path of a wave as a result of the change in wave speed
refraction
the spreading out of a wave after it passes around an obstacle or through a narrow gap
diffraction
the mutual reinforcement or cancellation that occurs when two or more waves meet
interference
when two crests or two troughs meet
constructive interference
when a crest meets a trough
destructive interference
when waves completely cancel each other out
complete destructive interference
the vibration traveling through a medium in the form of longitudinal pressure waves
sound
the strength of a sound wave
intensity
the effect of intensity on the way the human ear perceives sound
loudness
a measure of sound intensity that better reflects perceived loudness
sound intensity level
the unit of sound intensity
Decibel
the effect of frequency on the way the human ear perceives sound
pitch
sound in the audible frequency range of human hearing
audible sound
sounds with pitches below the audible range
infrasonic
sounds with pitches above the audible range
ultrasonic
the change in frequency caused by an object’s motion
Doppler effect
Speed of sound at 0℃ is ___
331 m / s
a speed above the speed of sound
supersonic
a speed below the speed of sound
subsonic
a violent compression pulse produced by constructive interference between waves produced by an object moving at supersonic speeds
shock wave
a loud noise caused by the shock wave from traveling at supersonic speeds
sonic boom
multiple reflections that cause persistence of sound
reverberation
a sound heard distinctly after being reflected from some object
echo
a system that emits sound waves underwater and analyzes the echoes reflected from submerged objects to determine the size, distance, and direction
sonar
the procedure for calculating distance by measuring the time interval that elapsed between the sending of a sound wave and the return of an echo
echo ranging
the process of dissipating the energy of sound waves in matter
absorption
the study of sound
acoustics
a series of organized sound waves with specific pitches that have been deliberately arranged
music
random sound with no intended pattern
noise
a sound of definite pitch
note
the difference in pitch between a musical note and a second note that has twice the frequency of the first note
octave
the result of two musical notes interfering harmoniously
consonance
the result of two musical notes interfering in a disagreeable way
dissonance
the distance between two notes
interval
a burst of louder sound occurring when interfering sound waves are perceived as a single pulsating sound
beat
the lowest-frequency of the different sounds produced when an instrument plays a note
fundamental
any of the sounds that are produced when an instrument plays a musical note and that are at higher frequencies than the fundamental
overtone
the series showing the frequency relationships between a fundamental and its overtones
harmonic series
the sound quality of a musical instrument
timbre
any frequency in the set of frequencies at which an object vibrates
natural frequency
a situation in which a driving frequency of an object is the same as or nearly the same as one of the object’s natural frequencies
resonance
an opening to a hollow body that is next to the strings or membrane
resonator
the time it takes for a wave to pass a point
period
the inverse of a period
frequency
the main factor affecting the speed of sound in air
temperature
formula for frequency
f = N / t (frequency = number of waves / time)
formula for speed
v = λf (speed = wavelength x frequency)
formula for period
T = t / N (period = time / number of waves)
