Waves and sound

SOUND and WAVES

SOUND and MOVEMENT

Sound is generated by a movement like shaking

your hands or blowing into

your instruments

In this photo we can see that waves of the sea have the same structure as sound waves.

TRANSVERSE AND LONGITUDINAL WAVES

SOUND AS LONGITUDINAL WAVE

● The sound is the alternation of compression and rarefaction of the air

● The uman being hears sounds between 20 Hz and 20000 Hz.

Nowadays we can hear music under water. For example, in some sports, like syncronized swimming thanks to this instrument (photo) athletes can dance under water.

● http://phet.colorado.edu/sims/wave-on-a-string/wave-on-a-string_en.html

Wavelenght and Amplitude● λ(lambda)=

wavelenght= distance between the two nearest peaks

● A=amplitude= distance between the peak and the orizontal line

FREQUENCY

● Frequency is the number of peaks in the unit of time, i.e. one second

Inserire grafico

Pure sound

Complex sound

THREE FEATURES OF THE SOUND

● PITCH● It depends on

frequency.● With a high

frequency you have a acue sound

● With a low frequency you thave a deep sound

● TIMBER● It depends on the different

forms of the waves● When two musical

instruments play the same note, we perceive a difference in the sounds and it depends on the different timbers

● INTENSITY● It depends on the waves energy● For example you increase the

intensity of a sound when you turn up the volume of your television or radio