Speed of sound in air at room temperature using a resonance tube

Sound can be contemplated as a longitudinal, mechanical wave and it can traverse through any channel. However, it can not traverse through the vacuum. No sound exists in a vacuum. The sound may exhibit variation in pressure. An area of heightened pressure on a sound wave is quoted compression (or condensation) and a region of curtailed pressure on a sound wave is quoted rarefaction (or dilation). 

Nature Of Sound

The sound elicited by a guitar is distinct from the sound elicited by a barrel. It is because the sound generated by several sources has distinct characteristics. Sound is continually illustrated by its frequency, wavelength, and amplitude. The medium during which it procreates can either be a solid, a liquid, or a gas. Sound propagates fastest in solids, quite slower in liquids, and slowest in gases. 

Characteristics of a Sound wave

• Crest and trough: In a wave, a top is referred to as the crest and a valley is called the trough.
• Wavelength: It is the gap between continuous compressions (C) or two continuous rarefactions (R). It is also represented via λ (Greek letter lambda). Its SI unit is metre (m).

• Oscillation: The change in density from the high charge to the high cost, but to the highest  rate, to make one complete oscillation. 
• Frequency: It is represented by means of ν (Greek letter, nu). Its SI unit is hertz (image, Hz).

• Time period of the wave: it is the time taken through  consecutive compressions or rarefactions to go a set thing.
• Its miles are represented via the manner of the photograph T, and its SI unit is 2nd (s).
• Frequency and term are related as follows:

ν = 1T

• Pitch: The faster the movement of particles of the source (or object which is producing sound), the higher is the frequency and the higher is the pitch.
• Amplitude of the wave: It is the magnitude of the maximum disturbance (clashing of particles) in the medium on either side of the mean value. It is shown by the letter A. Its unit is that of density or pressure. 

• The hardness(you can also say loudness) or softness(or you say sweet voice) of a sound is determined basically by its amplitude. 

• A sound wave spreads out from its source. As it goes far from its source you will listen to less sound because its amplitude as well as its loudness decreases. 

• Quality or timber of sound: It helps to distinguish one sound from another having the same pitch and loudness. 

• The sound, which is more pleasant to hear as compared to others, is said to be of a rich quality. 
• A sound of a single (or you can say 1 or unity)  frequency is called a tone. 
• The pleasant sound produced due to a mixture of several frequencies (so many sounding mixing with each other) is called a note.
• Noise(disturbance) is unpleasant to the ear.

• Intensity of sound: It is the amount of sound energy (number of frequency or you can say number of cycles passess through)  passing each second  through the unit area (you can say point).

Speed of sound in different media

• Sound propagates (vibrates) through a medium(or you can say in common term object) at a finite speed. 
• The speed of sound depends on the properties of the medium(particular object) through which it travels.

The speed of sound decreases from solid (include metal,non metal) to gaseous state (air).

Within a medium, the speed of sound increases with an increase in temperature(if you increase temperature molecules gain kinetic energy, it makes them collide to each other more fast and more impactful)

Reflection of Sound

The law of reflection of sound describes that the directions in which the sound is incident (touching object) and reflected (after touching that object bounceback) make equal angles with the normal to the reflecting surface at the point of incidence, point of reflection and normal (dividing line between incident line and reflected line) line lie on the same plane.

Echo: Echo is the reflection(repetition) of sound that arrives at the listener with a delay after the direct sound.

• The sensation of sound processes and sends to our brain for about 0.1 s.
• To hear an echo easily, the time interval between the original sound and the reflected sound should be at least 0.1s..
• The total distance covered by the sound from the point where it is created to the reflecting surface and back should be at least:

344 m/s × 0.1 s = 34.4 m (here, 344 m/s is the speed of sound)

• For hearing echoes impeccably, the reciprocal distance of the hindrance from the source of sound must be half of this distance, that is,17.2m. 
• This distance changes with varying temperature of gas.
• Echoes can be heard more than one due to multiple and successful reflections
• The roaring of thunder can be heard by the person due to successful reflection on multiple surfaces.

Doppler effect formula

The Doppler effect formula can be used to compute the velocity of the source and observer, as well as the original and observed frequencies of the sound waves. While there is only one Doppler effect formula, it changes based on the observer’s or sound source’s velocities in different scenarios. This is the Doppler effect formula:

f’=(v + vo)(v – vs) f

Here, f’ = observed frequency

f = actual frequency

v = velocity of sound wave

vo = velocity f the observer

vs  = velocity of the source

Conclusion

Sound is a type of energy that causes the sensation of hearing. It is also a type of energy that is generated by vibrations. Sometimes, we listen to more than one echo from a supply of sound if the region is big and has more than one reflecting surface consisting of valleys and huge empty rooms. This phenomenon is referred to as reverberation.