The nature and the properties of the sound waves

The sound wave

 

The sound

 

You should know that the sound is an external factor that affects the ear causing the sense of hearing . And it produced due to the vibration of the bodies , and it stops when the vibrating bodies stop their vibration .

 

The nature of the sound waves

The sound waves propagate through media as spheres .

It is very important to know that the sound waves are mechanical longitudinal waves which need a medium to propagate , They propagate through media as spheres whose centre is the source of the sound , And they consists of the compressions and the rarefactions .

 

The sound waves consists of the compressions and the rarefactions .

You notice that we hear the sound from all the directions that surround the sound source because the sound travels through the air as pulses of the compressions and the rarefactions whose centre is the sound source .

 

The sound velocity 

 

You should know that the sound velocity is the distance which is covered by the sound waves in one second , And the sound waves propagate through the different media with the different velocities  .

 

You know that the sound travels through the air at velocity 340 m / s , And it depends on the temperature of the air , The air pressure , and the humidity in air . 

 

You know that the sound velocity through the solids is larger than that through the liquids , And the velocity through the liquids is larger than that through the gases .

The sound waves are mechanical longitudinal waves .

The properties of the sound waves 

 

You should know that the sounds may be pleasant to our ears such as the music , And they may be the source of the fear such as the sound of the strong winds and the thunder .

 

They may be the source of the disturbance and the irritation such as the horns and the loudspeakers .

 

You should know that the sounds can be classified into two groups which are the musical tones and the noise .

The noise

It is very important to know that the musical tones are the tones of the uniform frequency , and comfortable to be heard . 

 

Examples : The violin , The piano and the reed pipe .

The violin is an example of the musical tones .

 

You should know that the noise is the sound of the non - uniform frequency , and  uncomfortable to be heard .

 

Examples : The drill , The loudspeakers , and the horn of the cars . 

The loudspeakers