SOUND• SHARIQ • IX H 32

WHAT IS A SOUND?•Sound is a mechanical wave that is n oscillation of pressure transmitted through a solid ,liquid ,or gas ,composed of frequencies within the range of hearing and of a level sufficiently strong to be heard or the sensation stimulated in organs of hearing by such vibrations.

PROPAGATION OF SOUND• Sound is a sequence of waves of pressure which

propagates through compressible media such as air or water. (Sound can propagate through solids as well, but there are additional modes of propagation). During their propagation, waves can be reflected, refracted by the medium. The purpose of this experiment is to examine what effect the characteristics of the medium have on sound.

PROPAGATION OF SOUND

SOUND WAVES•A sound wave is the pattern of disturbance caused by

the movement of energy traveling through a medium (such as air, water, or any other liquid or solid matter) as it propagates away from the source of the sound. The source is some object that causes a vibration, such as a ringing telephone, or a person's vocal chords.

SOUND WAVES

SOUND AND MEDIUM• Sound is a mechanical wave that results from the back and

forth vibration of the particles of the medium through which the sound wave is moving. If a sound wave is moving from left to right through air, then particles of air will be displaced both rightward and leftward as the energy of the sound wave passes through it. The motion of the particles is parallel (and anti-parallel) to the direction of the energy transport. This is what characterizes sound waves in air as longitudinal waves.

SOUND AND MEDIUM• Sound needs a medium to travel .It cannot travel

through vaccum.• Each vibration compresses the molecules and that

compression propagates onwards. In order for sound to exist, we need something to be compressed. In space, the particles floating about probably aren't close enough to compress and make anything audible

SPEED OF SOUNDMATERIAL SPEED OF SOUNDRUBBER 60m/sAIR 355m/sLEAD 1210m/sGOLD 3240m/sGLASS 4540m/sCOPPER 4600m/sALUMINIUM 6320m/s

WHAT IS WAVELENGTH?• Forms of electromagnetic radiation like radio waves, light waves or

infrared (heat) waves make characteristic patterns as they travel through space. Each wave has a certain shape and length. The distance between peaks (high points) is called wavelength.

THE END……