THE MUSIC OF SOUND

THE MUSIC OF SOUND
Sound :
Sound is a form of energy which produces sensation of hearing in our ears.

Production of sound :
Sound is produce due ti vibrations of an object such as a stretched membrane or a string under tension.

Waves:
A wave is a disturbance movng through a medium when the particles of the medium set neighbouring particles in motion .A wave motion is a mode of transmission
of energy through the medium .A wave in ehich the particled of the medium oscillate (vibrate)about their mean positions in a direction perpendicular to the direction of wvae
propagation is called a transverse wave .
A wave in which the particles of the medium oscillate (vibrate ) about their mean posiotions in a direction parallel to the direction of wave propagation is called a longitudinal wave.
The particles do not move from one part to another part of the medium.

Propagation of sound :
Sound requires a medium for propagation  .i.e. ,it cannot travel through vaccum. Sound propagetes in the fom of longitudinal waves.
As sound propagates through a medium,there is a change in the density and pressureof the medium.
Compressions are regions of highestpressure as well as highest density and rarefactions are regions of lowest pressure as well as lowest density.

 Range of hearing in humans :
The range of hearing in humans is from 20 Hz to 20000 Hz.

Infrasound and ultrasound:
The sound of frequency less than 20 Hz. is called infrasound and that of frequency more than 20000 Hz. is called ultrasound.
We cannot hear infrasound and ultrasound.
Ultrasound are used 1) to establish ship to ship communication
2)for welding plastic surfaces
3) to kill bacteria in liquids like milk to preserve them
4)in echocardiography
5) for imaging internal organs of the human body
6) in industry to clean parts of a machine
7) to detect cracks and flaws in metal blocks.

Reflection of sound :
Sound waves follow the same laws of reflection as followed by light waves .
The directions in which sound is incident and reflected make equal angles with the normal to the reflecting surface at the point  of incidence and the three are in the same plane.

Echo and reverberation:
Repetition of sound due to reflection of original sound from a surface is called echo.
The sensation of sound persists in our brainfor about 0.1 second.
The speed of sound in air at 22 degree Celsius is 344 m/s.
Hence ,for hearing distinct echo ,the minimum distance of the reflecting surface from the souce of sound must be 17.2 m in air at 22 degree Celsius .
The persistence of sound due to repeated reflection of ssound in a big hall or an auditorium is called reverberation.

SONAR:
Sound Navigation And Ranging (SONAR) refers to determination of the distance and location underwater objects using ultrsonic waves.

The human ear :
The human ear converts pressure variations in air with audible frequencies into electrical signals that travel to the brain ,via th eauditory nerve.Hence ,we can hear sound.

Frequency = 1/ time period

Speed of sound = frequency  *  wavelength

Solid Waste : Ecofriendly Management

Solid Waste : Ecofriendly Management
Solid waste is any unwanted and discarded material created by human beings

Solid Waste Management :

1) Waste can be  a resource , if it is managed properly and wisely .
2) If disposed carelessly , it becomes a major source of pollution of soil and water .
3) Generation of solid waste can be linked with economic growth ,environmental degradation ,health hazards,pollution of air ,water and land and destruction of human habitat.
4) More than 5000,1700 and 900 tonnes of solid waste per day , is created in Mumbai , Pune and Nagpur respectively .Mismanagement of solid waste resulted in heavy floods of 26th July 2005 in Mumbai.
5) E-waste is generated by electronic goods like discarded computers , TV sets and  mobile phones.5 tonnes of e- wastes is generated daily in India.
3)Classifation of soild waste:
1) Soild wastes can be classifield according to the source of waste or according to its biodegrabilitty.
2) According to source :
Domestic , industrial , hazardous, agricultural or garden, electronic, urban wastes and plastiic ,are different types of soild waste.
3) Biodegradable or decompossible and nonblodegradable or nonblodegradable are two types of solid wastes.
4) Dry solid wastes and wet solid wastes are also two types of solid wastes.
4) Effects of improper management of solid wastes:
1) Loss of aesthetic effect or beauty.
2) Bad odour / smell.
3) Release of toxic gases.
4) Spread of diseases.
5) Enviranmental pollution- water and solid pollution.
6) Effect on bird diversity.
5) E- wastes:
Electronic wastes contains heavy metals such as lead , beryllium, mercury and cadmimum. They remain accumlated in thr non- biodegradability causing adverse effects on human health and solid oranganisms.
6) Biomedical  wastes:
It is a highly infectious wastes due to the presence of pathogens. It can cause viral ,allergic , bacterial infections and skin dieaeses.
7) Plastic wastes:
Ot is a major concern of solid wastes mangement. The wide and irresponsible use of plastic ,leads and to choking of sewers.
Hareful for solid micoroorganisms. Burnimg of plantic can also lead to toxic gas emissions.
8) Industrial wastes:
Dumping and burning of this hazardous wastes can cause air and water pollution.
9) Comman methods of solid wastes management:
1) Collection of household wastes from door-to door as done by Municipalities.
2)Land fill.
3) Disposal in the sea.
10) stages of proper solid wastes disposal:
1) Wastes separation and segregation.
2) Transportation.
3) Ecofriendly methods
4) Composinting
5)Vermicomposting
6) Secured landfill
7) Pyrolsis
8) Energy recovery from domestic and industirial wastes.
9) Industrial solid wastes mangrmant
10) Biomedical wastes mangemant
11) Incinerator
11) Role of industrial and good habits in management of solid wastes:
1) Following 3 ' R's - Reduce, Reuse and Recycle.
2) We should adopt good habits as far as should wastes managements is concerned.
3) By spreading social awareness and personal discipline, the problem of solid wastes disposal can be reduced.