Speed of sound propagation

We know that sound waves flow across a medium by contracting and expanding the medium’s sections in alternating patterns. The speed of sound is defined as the pace at which sound waves propagate across a medium. In this article, you’ll learn about the definition of sound speed and the elements that influence it.

What is sound?

Sound is a sort of energy, just like heat, electricity, and other forms of energy. As an example of a sound source, consider the sound of a bell. When we ring a bell, it produces a sound. The object’s body moves back and forth due to the vibration that follows the sound.

Sound is a vibration that travels through solid, liquid, and gas mediums as an acoustic wave, with the medium contracting and expanding alternately.

Characteristics of sound

Sound is graphically depicted as a succession of peaks and troughs. A wave’s wavelength is the distance between two consecutive peaks or troughs. The frequency of sound is defined as the number of cycles covered per unit of time. The unit of measurement is the Hertz.

What is the speed of sound?

The dynamic propagation of waves via a variety of mediums is what it’s called. Depending on the medium through which it travels, sound travels at varying speeds. We’re talking about the speed at which sound waves travel through an elastic material when we talk about sound speed.

The following is the formula for the speed of with regard to gases:

ν=γP

Where,

• = the speed of sound
• = coefficient of adiabatic expansion
• P = pressure of the gas
• = density of the medium in which sound travels

Factors affecting the speed of sound

The following are the primary factors that influence the sound’s speed:

• The density of medium: Sound requires a medium to travel. One of the factors that determines sound speed is the density of the medium. The higher the density, the faster sound travels through the medium. On the other hand, the lower the density, the slower the sound propagation speed. This indicates that in different media, the speed of sound varies directly with the density of the medium.
• The temperature of the medium: The speed of sound is directly proportional to the temperature. As a result, as the temperature rises, the speed of sound increases.

Speed of sound in different 

The speed of sound is determined by the density and elasticity of the material through which it travels. Solids travel faster than liquids, but liquids travel faster than solids. The greater the elasticity and the smaller the density of a medium, the faster sound travels through it.

Speed of sound in solid

Sound is nothing more than a disruption caused by particle collisions, such as one molecule colliding with another, and so on. Solids are denser than liquids or gases, which means that the molecules in solids are closer together than in liquids, and liquids are closer together than gases. Because of their near proximity due to density, they can collide extremely rapidly. In practice, it takes less time for a solid molecule to collide with its neighbouring molecule. The speed of sound in a solid is faster than in a gas because of this advantage.

The sound speed in solids is 6000 metres per second, while steel has a sound speed of 5100 metres per second. Another fascinating fact about sound speed is that it travels 35 times quicker in diamonds than it does in air.

Speed of sound in liquid

In the same way, the density of a liquid is higher than that of a gas. As a result, the distances between molecules in liquids are greater than in solids but are smaller than in gases. As a result, the speed of sound in liquids is halfway between that of solids and gases.

Speed of sound in water

Sound travels faster in water than in air, and sound travels faster in water than in air. In water, sound travels at a speed of 1480 metres per second. It’s also worth noting that with distilled water, the speed can range from 1450 to 1498 metres per second. When the temperature is between 20 degree Celsius and 25 degree Celcius, the speed of saltwater is 1531 metres per second.

Speed of sound in gas

When sound enters a liquid or solid, we must remember that its speed is independent of the density of the medium. Because gases expand to cover a given space, their density is largely uniform regardless of gas type, but solids and liquids are not. The square root of the absolute temperature determines the speed of sound in gases (measured in Kelvin). It is, however, unaffected by the frequency of the sound wave, as well as the pressure and density of the medium. However, none of the gases we encounter in real life are perfect gases, and as a result, their properties vary significantly. At 20 degrees Celsius, the speed of sound in air is 343.2 metres per second, or 1,236 kilometres per hour.

Speed of sound in vacuum

In a vacuum, the speed of sound is zero metres per second since there are no particles present. When there exist particles for the propagation of sound waves, they travel through a medium. Sound waves cannot propagate in the vacuum since it is an empty space.

Conclusion

Sound waves in solids are made up of compression waves (as in gases and liquids) and a particular type of sound wave called a shear wave (which only occurs in solids). Shear waves in materials travel at different speeds than compression waves, as proved in seismology. The speed of compression waves in solids is determined by the compressibility, shear modulus, and density of the medium. Shear wave speed is exclusively determined by the solid material’s shear modulus and density.

In fluid dynamics, the sound speed in a fluid media (gas or liquid) is used as a relative measure of the speed of an item moving through the medium. The ratio of an object’s speed to the speed of sound is its Mach number (in the same medium). Objects travelling faster than the speed of sound (Mach1) are said to be supersonic (Mach1) (Mach1).