The kind of waves that travel fastest through a long metal rod have
Conduction | heat | physics
The explanation for this is that the Electro-Magnetic force, which connects the atoms of the pole together, must be transferred from one end of the pole to the other. Since the EM-transmitter force’s is light, the signal can’t go faster than light; instead, the pole would bend because the near end has shifted and the far end hasn’t yet received intelligence of the shift.
Atoms can be compared to the next-door neighbors. If one of them wishes to relocate, he sends a message to all of his immediate neighbors informing them of his decision. Then they all decide to move, so they each send out messengers to their nearest neighbors to inform them of their intentions; and so on, until the message to relocate has reached its destination. No atom will move before he receives the message to do so, and the message can only fly as far as all of the messengers can go, which is faster than the speed of light.
At the other hand, knowledge about the pushes will be obtained at the speed of sound in the pole’s substance. It is much slower than the speed of light for any specific material (about 5000 m/s for a steel rod).
Propagation of sound
The microphone circuit generates a pulse with the leading edge of each loop when the signal generator generates a square wave. Placing the microphone directly against the speaker’s output grille reveals a 210-second delay inside the speaker housing. Measuring from the flat face of the speaker housing might account for this delay reasonably well, but measuring from the grille and subtracting 210 seconds from the travel time removes it completely.
A disruption in an elastic medium produces sound waves, which are longitudinal waves. In contrast to a transverse wave, where the oscillatory motion of the particles transmitting the wave is perpendicular to the direction in which the wave moves, the oscillatory motion of the particles transmitting the wave is parallel to the axis along which the wave travels. The elastic medium in this situation is, of course, air or, whether the tube is filled with hydrogen, helium.
Now imagine a single compression pulse being sent down the tube, with well-defined edges and consistent density and pressure. Gas is coming into the pulse at velocity v as it passes through the tube in the frame of reference of the pulse. As a thin slice of gas reaches the area where the pulse is, the leading face is at a higher pressure than the trailing face, compressing and decelerating the gas. It has a pressure difference of dp and a velocity of v + dv within the pulse field. (dv stands for negative.) It experiences the reverse pressure difference when it emerges from the other side of the pulse field, extends, and accelerates to its original velocity, v.
Speed of sound in solids, liquids, and gases – physics
When one end of a long metal bar is bumped, the other end does not shift immediately. If the bar were completely rigid, the movement would be instantaneous, but perfect rigid materials are fundamentally impossible in the real world. While the bar’s movement appears to be uniform and instantaneous to our eyes, it is not. Our eyes are actually too slow to note the quick but not instantaneous series of events that occurs.
When you bump one end of a bar, you just distort the end locally at first, leaving the rest of the bar untouched. However, by inwardly deforming the near end of the bar, you’ve developed a high-pressure zone surrounded by low-pressure zones. To put it another way, you’ve pushed the atoms at the bar’s near end closer together than their chemical bonds’ equilibrium positions. Simply put, the first few layers of atoms have collided with the next few layers of atoms. So, what’s next?
The bar’s close end, which is at a higher pressure, presses against a lower-pressure section farther down the bar, causing it to have a high pressure. As a result of this operation, you’ll have a pressure wave running down the length of the bar until it hits the far end. The term “sound” is widely used to describe such a pressure wave. When you bump one end of the bar, you actually produce a sound wave that ripples down the bar. It’s not a constant sound wave like the tone of a flute, but it’s still a sound wave. The far end of the bar does not move until the sound wave reaches it and causes it to move. Since a sound wave carries the “message” that the bar has been bumped to the entire bar, such a setup could only be used to transmit messages at the speed of sound. Sound travels at a much slower rate than light and is certainly not instantaneous. What exactly is this tidal wave of pressure? It’s a domino effect caused by atoms’ chemical bonds being squeezed, springing back to equilibrium, and yanking their neighbors in the process. In the most basic scenario, the first layer of atoms knocks into the next layer and causes it to move, and then knocks into the layer after that, and so on.
How sound travels across different mediums
Assume you’re deep underground in a long mining tunnel. You have a mate in the tunnel who is thousands of feet away from you. You order your friend to shout and clang on the pipes on the tunnel floor at the same time using a walkie talkie. To find out what happens, click the play button below.
Sound does not always travel at the same pace. Keep in mind that sound is the vibration of kinetic energy transferred from one molecule to the next. The closest the molecules are to one another and the stronger their bonds are, the less time it takes for them to transfer sound between them and the faster sound can fly. Since the molecules in solids are closer together and more closely bonded, sound waves pass through them more easily than through liquids. Sound travels more slowly through gases than through liquids since gaseous molecules are closer together. In solid materials, sound travels quicker, and in liquids or gases, it travels slower. Two properties of matter influence the velocity of a sound wave: elastic properties and density. The following equation describes the relationship.