What is the propagation of sound in solids? 5

Knock on the wooden block, which spreads in both solids and gases. What you hear is airborne propagation, because you can't be immersed in solids. It can also be understood as liquid, if the water is solid, and you soak in the water, then the sound you hear is transmitted through the solid (water) to your ears, but eventually through the air, because the ear canal cannot be soaked in water.

Propagation in different mediums is just different velocity. For example, if you hit one end of a hollow iron pipe and you listen to it at the other end, you will hear two tapping sounds. Because sound travels fast in solids and slow in air.

Spreads simultaneously in wooden blocks and in the air. For example, if you hit a railroad track and listen to it from a distance, what you hear in the air is airborne, and what you hear when you lie on the railroad track is it transmitted in solid.

The first thing is that it is the vibrations that are propagated, and the vibrations propagate both in the wood and through the air. Both propagate vibrations.

When knocking on wood, the vibrations of the vibrator are propagated outward by the air on the one hand, and at a distance through the wood on the other.

For example, a long piece of wood, struck from this end, can transmit vibrations through the wood to the other end. ）

You take a stick and hit others and knock yourself, which is the best example of sound propagating in the air against ships and solids, and it is very simple to operate, try it, you can feel the different effects of sound transmission in both media.

How Sound Travels

Sound propagation is not like light, it requires a medium, and the denser the medium, the faster it travels, because the density of solids is the highest, so sound travels faster in solids than in liquids.

As long as the frequency of the wave source does not change, the frequency of the wave does not change. The speed of the wave is determined by the medium, for example, the speed of sound propagation in air is not the same as that in water, and the speed of sound propagation in air is the slowest compared to other common media (such as solid liquids).

According to v = f (v is the wave speed, wavelength, f is the frequency), it is concluded that whether the wavelength of the wave changes, as long as the medium through which the wave passes is uniform, the inhomogeneous wavelength changes, and the uniform wavelength does not change.

So in the air, it depends on the medium.

OK. Sound is a wave generated by the vibration of an object, which is a wave phenomenon that travels through a medium (air or solid, liquid) and can be perceived by the auditory organs of humans or animals. An object that initially vibrates (vibrates) is called a sound source, and sound is transmitted in the form of a wave.

Sound is the motion formed by the propagation of sound waves through any medium.

The principle of sound production

Sound is a pressure wave: when a musical instrument is played, a door is slammed or a table is struck, their vibrations cause the medium-air molecules to vibrate rhythmically, causing the surrounding air to produce dense changes to form sparse longitudinal waves, which produce sound waves, and this phenomenon continues until the vibration disappears.

As a kind of wave, frequency and amplitude have become important properties to describe the wave, the magnitude of the frequency corresponds to what we usually call pitch, and the amplitude affects the magnitude of the sound. Sound can be broken down into superpositions of sine waves of different frequencies and intensities. This process of transformation (or decomposition) is called the Fourier transform.

Therefore, sound in general always contains a certain frequency range. The frequency range of sounds that can be heard by the human ear is between 20 and 20,000 hertz. Fluctuations above this range are called ultrasound, while those below this range are called infrasound.

Animals such as dogs and bats can hear sounds up to 160,000 hertz. Whales and elephants produce sounds with frequencies in the range of 15 to 35 Hz.

The propagation of sound is explained by quantum mechanics as the movement of atoms, which forms sound waves. But this is not related to nouns such as wave particles.

Yes. If only the material is considered, the solid sound transmission is mutual.

However, if you take into account the shape, the result will be a little different, and you can refer to the structural design of the flaring and sound-attenuating laboratory.

The essence of sound is vibration, and since it can be transmitted, it can be transmitted. It's not possible to shake this out of a single motion and it's not the same as an analog signal.

A medium is required for sound propagation, and the denser the medium, the faster it travels, because solids have the highest density, so sound travels faster in solids than in liquids.

The propagation of sound in a medium depends on the collision of particles in the medium, and the faster the speed is when the direction of the collision is more likely to coincide with the direction of sound wave propagation.

In gaseous liquid solids, these particles are usually molecules or atoms (collectively referred to as molecules for convenience). The most basic difference between the three states of matter of gas, liquid, and solid is the average free path of the molecules, or the degree of binding, or the average spacing. The free path of the irregular movement of the molecules in the gas is large, that is, the distance they run before the next collision is long, that is, the waiting time for the next collision is long, so the propagation of mechanical waves naturally takes longer.

The average free path of liquids is much smaller, the molecules are only fixed in a small area to vibrate, and the time required for the next collision is shorter, so the mechanical wave travels faster. Solids have a smaller average free path than liquids, so they propagate faster.

So from a macroscopic point of view, in general, in terms of density, solid, liquid, and gas, so this situation will occur. However, it is not absolute, so it is not entirely correct to distinguish the speed of sound by density, such as water and ice. But ice is known to be less dense than water.

After experiments, we already know that temperature also contributes greatly to the propagation of the speed of sound, and generally the temperature of the same medium increases with the speed of sound, of course, this can be explained by the increase in temperature and the acceleration of molecular vibration. In addition, there is the problem of materials, shape, doping, etc., which can change the speed of sound propagation.

Therefore, the speed of sound propagation has a lot to do with the interaction between the molecules in the medium, if the interaction of the molecules in the medium is very strong, then the speed of propagation is relatively fast, on the contrary, if it is weaker, even if the density is relatively large, the speed of sound propagation will not be very high. (e.g. iron and lead).

Solids transmit sound by vibration.

An object that initially emits vibrations (vibrations) is called a sound source. Sound travels in the form of waves that vibrate (vibrate). Sound is the motion formed by the propagation of sound waves through any substance. Because the sound emitted by each object is different when it vibrates, different vibrations produce different sounds.

Since the sound is at room temperature, the sound velocity in the air is about 345m s, which belongs to the same propagation medium. As a result, the last sound heard in the air is as fast as the sound it was made at the beginning.

Because the frequency and amplitude of transmission are the same, because they are the same material, they do not change much, and when transmitted to the brain, there is a small difference that people cannot distinguish, resulting in almost the same thing as being heard.

Finally your ears are airborne.

Solids transmit sound by vibration.