17.1 Sound

The person observing the shift heard a sound.

The objects are moving faster than the sound.

Sound interference and resonance can be defined as standing waves in air columns.

Sound interference occurring inside open and closed tubes changes the characteristics of the sound, and this applies to sounds produced by musical instruments.

Sound wave measurements can be used to calculate the length of a tube.

Explain how the inner ear relates to sound perception.

Density values are used to calculate acoustic impedance.

The velocity of a moving object can be calculated.

The answer depends on how you define sound.

There was no sound if sound only existed when someone was around to hear it.
There was a sound even if nobody was around to hear it.

The wave is called sound.

Its perception is being heard.
The physical phenomenon and its perception will be considered in this text.
Sound and hearing are related, but not the same thing.
We will look at how sound waves can be used in medical scans.

The glass has been shattered by a high-intensity sound wave.

The effects of the sound prove that it exists.

Hearing is one of our most important senses, so it's interesting to see how sound's physical properties correspond to our perception.
Sound has applications beyond hearing.
It is not heard but can be used to form medical images and also be used in treatment.

On the atomic scale, the atoms are more ordered than their thermal motions.

In many cases sound is a periodic wave and the atoms are moving.
We will explore periodic sound waves in this text.

As the string moves back and forth, it transfers energy to the air.

A small part of the string's energy goes into expanding the surrounding air, creating higher and lower local pressures.
The compressions and rarefactions move out as longitudinal pressure waves have the same frequencies as the string.

The air behind it is compressed by a vibrating string moving to the right.

As the string moves to the left, it creates another compression and rarefaction as the ones on the right move away.

A series of compressions and rarefactions move out from the string as a sound wave.

The distance from the source is shown in the graph.
Ordinary sounds have slightly different pressures than atmospheric ones.

The energy of a sound wave is spread over a larger area, so the sound wave's amplitude decreases with distance from its source.

During each compression and rarefaction, a little heat transfer to the air and a lot of heat transfer from the air, so that the heat transfer reduces the organized disturbance into random thermal motions.
Waves are important for sound as they are for all waves.

The eardrum vibrates when sound wave compressions and rarefactions travel up the ear canal.

The eardrum has a net force due to the sound wave pressures and the atmospheric pressure behind it.
The person's nerves are converted to nerve impulses by a complicated mechanism.

The interference pattern can be created by adding a second source or a pair of slits.

Light energy is perceived before sound when a firework explodes.

Sound travels more slowly than light.

You can see the speed of sound when watching a fireworks display.

The flash of an explosion is seen before the sound is heard, implying that the sound is slower than light, and that it travels at a finite speed.
You can hear the sound of a sound.
The correlation of the size of musical instruments with their pitch is indirect evidence of the wavelength of sound.
Large instruments, such as a tuba, make low-pitched sounds while small instruments, such as a piccolo, make high-pitched sounds.
The size of a musical instrument is related to the wavelength of sound it produces.
A small instrument makes sounds.
Arguments hold that a large instrument makes long-wavelength sounds.

The number of waves that pass a point per unit time is the same as the source.

A sound wave is created from a source vibrating at a Frequency and has a wavelength.

The table shows that the speed of sound varies greatly.

The speed of sound is determined by the density and rigidity of the medium.
The sound energy is easier to transfer from particle to particle in materials with similar rigidities.
The air has a low speed of sound.
The speed of sound in liquid and solid media is higher than in gases because of their rigidity.

The speed of sound depends on the rigidity of the medium in which it is made.

The longitudinal component of an earthquake travels at different speeds.

The bulk modulus of granite is greater than the shear modulus.

The speed of longitudinal or pressure waves in earthquakes in granite is higher than the speed of shear waves.
The components of earthquakes travel slower in less rigid material.
S-waves range in speed from 2 to 5 km/s and P-waves range in speed from 4 to 7 km/s.
As they travel through Earth's crust, the P-wave gets closer to the S-wave.
The time between the P- and S- waves is used to determine the location of the epicenter of an earthquake.

The temperature of the medium affects the sound's speed.

The Boltzmann constant is the mass of each particle in the gas.

The speed of sound in air and other gases should be determined by the square root of temperature.
This is not a strong dependence.
The speed of sound is 331 m/s, which is less than 4% higher.
Medical images can also be used with echoes.

A bat uses sound echoes to find its way.

The time for the echo to return is determined by the distance.

The speed of sound is nearly 888-609- 888-609- 888-609- 888-609- 888-609-

If this independence were not true, you would notice the music being played by a marching band in a football stadium.

The sound from the low-pitched instruments would lag behind the high-pitched ones if the high-frequency sounds traveled faster than you were from the band.
All frequencies must travel at the same speed because the music from all instruments arrives in a different rhythm.

In a given medium under fixed conditions, is constant, so that there is a relationship between and.

Because they travel at the same speed in a given medium, low-frequency sounds must have a greater wavelength than high-frequency sounds.

The lower-frequency sounds are emitted by the large speaker, while the higher-frequency sounds are emitted by the small speaker.

The audible range is 20 and 20,000 Hz.

We can find the wavelength from the frequencies.