science presentation of sound ch 13
TRANSCRIPT
1.Topics to be covered :
Sound
Production of sound and How sound travels
Sound produced by humans
Sound produced by musical instruments
How humans hear sound
Amplitude ,time period and frequency of vibration
Loudness and Pitch
Amplitude , time period and frequency of a vibration
Audible and Inaudible sounds
Noise or Music
Noise pollution.
2.Sound:
Vibrations that travel through the air
or another medium and can be heard
when they reach a person's or animal's
ear are called Sound.
3.Production of sound and how sound
travels :
Sound is produced by a vibrating body.
The to and fro motion of an object is called
vibration.
When a object stops vibrating ,it does not
produce any sound.
5.Sound produced by musical
instruments:
In musical instruments sound is produced with
the help of vibrating parts.
In different musical instruments different
parts vibrate to produce sound
Eg. In tabla stretched membrane vibrates to
produce sound ,in flute air column vibrates to
produce sound ,in sitar strings vibrate to
produce sound.
6.How humans hear sound:
Human and every animal hears sounds through their ears.
Sound Waves enter the ear canal and cause the eardrum to vibrate. Vibrations pass through three connected bones in the middle ear. This motion Sets Fluid Moving in the inner ear.
7.Amplitude ,time period and Frequency
of a vibration:
Vibration is the to and fro motion of a object . It is also called
oscillatory motion of a object.