Sound can reverberate in air, but can it be in solids? 25

Yes, in fact, only when there is an obstacle, there is an echo, but sometimes you can't hear it. When a sound is generated, it reaches your ears right away, and that's the first sound. Then the sound comes out, it travels in the solid, it hits an obstacle and it is reflected back into your ears, this is the second sound, if the time between the two sounds entering your ears is more than a second, you can distinguish them, hear two sounds, otherwise you can only feel one. We don't usually experience this kind of solid echo phenomenon, but you live in the air.

The speed of propagation is directly related to the composition of the air.

Generally speaking, the denser the object, the faster the sound travels in it. Therefore, the speed at which sound travels in matter is "liquid" solid. If the medium states are the same, such as gases, the denser the gas, the faster the sound travels.

We know that air is not pure, but a mixture of ingredients. It contains nitrogen, oxygen, carbon dioxide, water vapor, noble gases and other components. The comparison between the most abundant substances and the average density of air, from largest to smallest, is:

Carbon dioxide, oxygen, average air density, water vapor, nitrogen.

Therefore, if the carbon dioxide or oxygen content is high in any place, the sound will travel faster than the normal air composition. If the nitrogen content is high in any place, the speed of sound propagation will be less than that of ordinary air composition.

The limit is that it is all a very dense gas such as carbon dioxide, but such a gas can no longer be called air

Note: 1The heaviest gas that air contains is radon, a noble gas that is found in very small quantities.

2.The speed of sound propagation is related not only to the composition of the air, but also to the temperature of the air. In the same way, the higher the temperature, the gas expands, the density decreases, and the speed at which sound travels decreases. So the propagation velocity at low temperatures is greater than at high temperatures.

As long as there is an obstacle, see if the reflected sound wave energy is enough, because most of it is 'absorbed' by the obstacle. The junior high school students are confused and solve oo

The sound does not have an echo when it encounters air, but continues to travel forward. Echo is when the sound is projected on a large area (obstacle) at a distance from the sound source, part of the sound energy is absorbed, and the other part of the sound energy is reflected back, if the listener hears the sound directly from the sound source and the sound reflected back by the time interval of more than one-tenth of a second, it can distinguish the two sounds, this reflected sound is called "echo". Sound cannot pass through a solid state, as explained above, sound is absorbed and reflected by a solid and if the size of the solid is close to or less than the wavelength of the sound wave, the sound wave will bypass the obstacle.

The sound will have an echo when it encounters an obstacle, and even if it can pass through, it will not pass through completely, and there will be **.

Sound can transmit energy. Sound travels in the air, and when it encounters a solid obstacle, only a small part of the sound energy is transmitted to the solid, and when it travels in the solid, most of the sound is still reflected back, and an echo is generated.

When the sound propagates when encountering obstacles, it will be reflected to form an echo, and at the same time, a small part of the obstacles, such as the partition wall has ears, and the sound heard by the partition wall is much smaller than that without the partition wall, because the sound is reflected.

Got it? I don't know how to ask again.

One part of the anti-propagation into the solid, and part of the reflection back!

When sound is propagating, the speed of propagation from one medium to another is to change, in this case, the reflection of sound is more powerful than the sound propagation through the mountain, in addition, sound waves have the ability to bypass some obstacles, we just hear the sound reflected from this side but can not feel the sound of the mountain at the same time!

Part passes through part reflection.

It's like light hitting an object and there are two phenomena of reflection and refraction at the same time.

This is the same as the reflection of light on glass.

Some of the sound waves rushed from the air to the mountain were also transmitted into the mountain, but most of them were reflected back.

First of all, you have to understand sound waves, which are caused by the vibration of the air, and can the air still penetrate into the mountain? It's just that the vibration of the air drives the vibration of the rock mass on the surface of the mountain, and the vibration of the rock mass on the surface of the mountain decays when it propagates inward, and it is very difficult to pass through the mountain

Sound travels faster in liquids and solids than in air.

The speed at which sound travels is also related to the temperature of the medium of propagation. The higher the temperature of the medium, the faster the propagation velocity.

The sound we hear with our ears is caused by the oscillatory motion of the atoms or molecules that transmit the sound. The vibrations push nearby molecules together and compress them. When the compressed molecules are separated, they cause compression in the adjacent region, so that this compression region seems to propagate outward from the sound source, and the speed at which the compressed wave travels outward from the sound source is the speed at which the sound travels in that medium.

The speed of sound depends on the intrinsic speed of motion of the molecules that make up the substance. For example, once a part of the air is compressed, the molecules will separate again due to their own inherent random motion, and if this random motion is fast, then the molecules of the compressed part will quickly separate and quickly compress the molecules of the adjacent part.

The molecules of the adjacent part also quickly separate and compress the next part quickly. So, in general, the compressed wave travels outward very quickly, so the speed of sound is high.

Anything that increases (or decreases) the natural velocity of air molecules increases (or decreases) the speed of sound in the air.

Coincidentally, air molecules move faster at higher temperatures than at lower temperatures. It is for this reason that sound travels a little faster in warm air than in cold air. It has nothing to do with density.

At 0, the freezing point of the water, the sound travels at a speed of 1193 kilometers per hour. For every 1 increase in temperature, the speed increases by about 2 2 kilometers per hour.

Generally speaking, if the molecules that make up a gas are lighter than air molecules, then the density of the gas is lower than that of air. Lighter molecules also move faster.

Sound travels faster in this light gas than in air, not due to a change in density, but due to the faster movement of molecules. The speed at which sound travels in hydrogen at 0 is about 4667 kilometers per hour.

When we talk about liquids and solids, the situation is very different from gases. In gases, the molecules are far apart from each other and hardly interfere with each other. If the molecules are pushed closer to each other, they are separated from each other simply by random motion, but in liquids and solids, the atoms and molecules are in contact with each other.

If they are pushed and pressed together, their mutual repulsion forces force it to separate again very quickly.

This is especially true for solids. In solids, atoms and molecules are more or less firmly held in their respective positions. The more they hold them firm, the faster they bounce back as they are pushed together.

As a result, sound travels faster in liquids than in gases; Spreads faster in solids; It spreads fastest in rigid solids. Density is not the root cause of how fast or slow sound travels. Thus, sound travels at a speed of about 5,200 kilometers per hour in water and about 18,000 kilometers per hour in steel.

Due to the medium, the distance between the molecules in the gas is very large, which is not conducive to the propagation of mechanical vibration, but the particles that make up the solid are arranged very closely, so that the mechanical vibration can propagate rapidly.

Because the sound that people hear is transmitted to the eardrum through sound wave vibration and then transmitted to the auditory nerve, after closing the door, the sound wave is blocked and weakened, and the sound propagates better in the harder the substance, the better, in the flexible medium, the amplitude of the sound wave is large, the consumption is large, and the propagation is slow.

The most obvious example is to use small pieces of explosives to fry fish, in the water a small bottle of explosives in the water can shock a large area of fish to death, of course, not fragments, you can see that the fish is basically not injured, but a small bottle of explosives in the air, even nearby flies can not be blown up. Unless there is direct contact.

With the same force, gently knock on a long steel pipe and listen to the other end of the steel pipe, the sound can be transmitted clearly, if you knock a short section of steel pipe at the same distance, the sound from the air is obviously weak.

First of all, the sound passes through the air, then through the door (solid), and then through the air, and the medium transformation affects the propagation of the sound.

If someone knocks on the door, you must hear a louder sound when you lie on the door than when you leave the door, which proves that the sound travels well in solids.

Whether the door is a wooden door or an iron door, the middle is not solid, and there is a sound-absorbing material stuffed inside, I don't believe you go to any store that sells doors to see the cross-section of the door.

This is still the sound in the air, and there is a door in the middle, of course, you can't hear it.

propagating in the form of waves; Echo is the phenomenon in which sound is reflected back when it encounters obstacles in propagation; 17 meters; Because the speed of sound is 340 meters per second. The person hears the sound seconds after the sound is made, and the sound wave goes back and forth at this time, so it should be (or.

You alright!!! o(∩_o

Sound travels through the air and requires a medium

When the sound encounters an obstacle in the process of propagation, it will be reflected back, and the reflected sound will be heard again by us as an echo.

17 meters; Because the speed of sound is 340 meters per second. The person hears the sound seconds after it is made. At this point, the sound wave is going back and forth. Therefore, twice the distance between the object and the person is the distance traveled by the sound. 340*0、

Sound propagation depends on the medium, which is transmitted from one mass to the next, and is passed down in turn, and the energy of sound decreases in the process. 17 meters;