1138 Questions & Blanks Flashcards
Why do some media conduct sound waves better than others?
Some have better elasticity.
How does the increase in temperature affect the speed of sound.
It increases the speed of sound.
Speed of sound
slow in air and wood
medium in alcohol, hydrogen, and water
fast in brass, granite, glass, and steel
insane in beryllium (over 9,000)
People can hear sounds roughly between:
20 and 20,000 Hz
What is sound intensity?
The quantity of energy passing through one cm^2 each second.
velocity = (frequency)(wavelength)
.
How is sound energy lost as sound waves expand?
Some sound is absorbed into the air and converted to heat energy
To what kinds of waves does the Doppler effect apply?
All
What property of waves is affected by reflection
direction
How does an echo differ from a reverberation?
An echo is a single repetition of an initial sound, while a reverberation is a prolonged rumble of many echoes.
What can be done in auditoriums to reduce echoes?
Install sound absorbent material
The ______________ allows sound waves to be collected and refocused
property of reflection
How is the use of radar similar to the use of a foghorn in detecting obstacles?
They both send out and collect waves.
How does sonar measure distances to underwater obstacles?
It measures the time that it takes for sound waves to return
How are seismic waves helpful to us?
studying the internal structure of the Earth
finding oil
What is refraction?
change in direction of a wave as it passes from one medium to another
When a wave enters a new medium, what will always change?
speed
Sound waves which lose speed as they enter a new substance bend _____________
toward the normal line
How does refraction affect sound at night?
It bends sound waves toward the ground
S = vt
.
The fundamental frequency of an object depends upon _____________
length
mass
tension
What is an overtone?
a sound with a pitch that is a simple multiple of the fundamental frequency
The third overtone is equal to the
fourth harmonic
the tenth harmonic is equal to the
ninth overtone
Define resonance
the inducing of motion that occurs when the vibrations produced by one object act upon a second object and cause it to vibrate as well
What must be true for resonance to occur?
if the fundamental frequency of two objects are the same or
if the vibration rate of one of them is an overtone of the other
Words used to describe a musical note
Pitch
Quality
Loudness
Upon what does the quality of a musical note depend?
the number and intensity of overtones
Human voices differ because of:
quality and resonance
The interaction of two waves is called:
interference
The things that typify music
Rhythm
Melody
Harmony
What effect does the length of a string have on the frequency produced?
longer strings have lower tones
shorter strings have higher tones
How do a guitar and a piano differ in producing a multitude of notes?
A guitar has a few strings which can be altered in length, while a piano has many strings of different lengths
Use to change the pitch of wind instruments
valves
tubes
slides
The difference between two frequencies of objects that are sounded together
beats
wavelength = length of object times 4
2.5 meter organ pipe = 10 m/wave
Under what circumstances does the inverse square law for sound fail entirely?
when the sound waves are not free to expand in a sphere
____ and ____ are synonymous
Pitch
frequency
