ppt

1. SOUNDSOUND
VIDYA G.VIDYA G.
Physical SciencePhysical Science
N.S.S TRAINING COLLEGE
PANDALAM
2014-2015

2. SOUNDSOUND
Sound is produced by the vibration ofSound is produced by the vibration of
material objects. Sound travels as waves. Amaterial objects. Sound travels as waves. A
medium is required for the transmission ofmedium is required for the transmission of
sound. The velocity of sound is different insound. The velocity of sound is different in
different media.different media.

3. Velocity of soundVelocity of sound
through certain mediathrough certain media
AirAir - 330 m/s- 330 m/s
WaterWater - 1435 m/s- 1435 m/s
WoodWood - 3850 m/s- 3850 m/s
IronIron - 5000 m/s- 5000 m/s

4. Limits of audibilityLimits of audibility
We cannot hear all sounds. Sound ofWe cannot hear all sounds. Sound of
frequencies between 1000Hz and 5000Hzfrequencies between 1000Hz and 5000Hz
are heard best by almost all people. It canare heard best by almost all people. It can
be said generally that for humans thebe said generally that for humans the
audible frequencies lie between 20Hz andaudible frequencies lie between 20Hz and
20000Hz20000Hz

5. Infrasonic andInfrasonic and
Ultrasonic soundsUltrasonic sounds
The frequencies above 20000Hz theThe frequencies above 20000Hz the
upper limit of audibility are calledupper limit of audibility are called
ultrasonics and frequencies below 20Hzultrasonics and frequencies below 20Hz
are called infrasonics.are called infrasonics.

6. Super sonic andSuper sonic and
SubsonicSubsonic
Speeds greater than the speed ofSpeeds greater than the speed of
sound are called supersonics and speedssound are called supersonics and speeds
lesser than the speed of sound are calledlesser than the speed of sound are called
subsonics.subsonics.

7. Super sonic andSuper sonic and
SubsonicSubsonic
Speeds greater than the speed ofSpeeds greater than the speed of
sound are called supersonics and speedssound are called supersonics and speeds
lesser than the speed of sound are calledlesser than the speed of sound are called
subsonics.subsonics.