Chapter 7 Flashcards
What is a periodic back-and-forth motion (or oscillation) that transmits energy?
Wave
What is the substance through which a wave transfers its energy?
Medium
What are the high points of a wave train?
Crest
What are the low points of a wave train?
Troughs
What are waves in which particles of the transmitting medium oscillate at right angles to the direction of wave travel?
Transverse Waves
What are waves in which the particles of the transmitting medium oscillate in the direction of wave motion?
Longitudinal Waves
What is the term for the squeezed portion of the coils of the spring?
Compression pulse
What is the term for the portion of the spring where the coils are spread out?
Rarefaction pulse
What is the length of a single wave?
Wavelength
What Greek letter represents wavelength?
Lambda (looks similar to a wishbone)
What is the term for the number of waves that pass a given point per unit time
Frequency
What is the SI unit of frequency?
Hertz
What is the time needed for one cycle of wave to pass?
Period
Formula for Period
Period = Time/Waves = 1/Frequency
Formula for Frequency
f = Waves/Time
What is the rate at which a wave travels through a medium?
Speed
Formula for Speed of a Wave
v = Lambda(f)
What is the change in the course of a wave as a result of a collision with an object of boundary?
Reflection
What states that the angle of incidence equals the angle of reflection?
Law of reflection
What is the bending of the path of a wave as a result of a change in wave speed?
Refraction
What is the spreading out of a wave after it passes through a narrow opening?
Diffraction
What is the reinforcement or cancellation that occurs when two or more waves meet?
Interference
What is the term for vibrations traveling through a medium in the form of longitudinal pressure waves?
Sound
What is the strength of a sound wave?
Intensity
What is the effect of intensity on the way the human ear perceives sound?
Loudness
What is the measurement used for sound intensity level?
Decibel
What is the effect of frequency on the way the human ear perceives sound?
Pitch
What is sound that can be heard?
Audible sound
What are sounds with pitches below the audible range?
Infrasonic sounds
What are sounds above the audible range?
Ultrasonic sounds
What is the change in frequency caused by object’s motion?
Doppler effect
What is the main factor affecting the speed of sound in air?
Temperature of air
What is a violent compression pulse caused by constructive interference?
Shock wave
What is the loud noise that sounds when a shock wave hits the ear?
Sonic boom
What are the multiple reflections that cause the persistence of sound?
Reverberation
What is a sound heard distinctly after being reflected from some object?
Echo
What system, developed during WWII to locate submerged enemy submarines, emits sound waves underwater and analyzes the echoes reflected from submerged objects?
SONAR (SOund NAvigation & Ranging)
What is the procedure for calculating distance by measuring the time interval that elapses between the sending of a sound wave and the return of an echo?
Echo ranging
What is the process of dissipating the energy of sound waves?
Absorption
What is the study of sound?
Acoustics
What is a series of organized sounds waves with specific pitches that have been deliberately arranged?
Music
What is random sound with no intended pattern?
Noise
What is a definite pitch produced by a singing voice or musical instrument?
Note
What is the difference in pitch between one note and a second note that is twice the frequency of the first?
Octave
What is the result of two notes interfering harmoniously?
Consonance
What are two notes that interfere in a more disagreeable way?
Dissonance
What is the distance between two notes?
Interval
What is the burst of louder sound that rapidly fades in and out?
Beat
What is the most dominant sound within a single note?
Fundamental
What are the other sounds produced at higher frequencies than the fundamental?
Overtones
What describes the frequency relationships between the fundamental and overtones?
Harmonic series
What is the distinct sound quality of each musical instrument or voice?
Timbre
What is the set of natural frequencies at which an object vibrates?
Natural Frequencies
What is the state in which two frequencies are the same or nearly the same?
Resonance
What reverberates the sound waves produced by the instrument to make the sound louder by resonance?
Resonator