THE PHYSICS OF SOUND

Playing Music With Palm Pipes (PCV)

WHAT IS SOUND?• Sound is a mechanical wave, or a wave that transfers

energy, that is a fluctuation of pressure transmitted through some medium (like air or water), composed of frequencies which are within the range of hearing• Sound is produced when an object creates vibration• Humans can hear within the range of 20 Hz to 20,000 Hz (Hz

or Hertz - is the unit of frequency or number of vibrations per second)• If the end of the tube is uncovered such that the air at the

end of the tube can freely vibrate when the sound wave reaches it, then the end is referred to as an open end. If both ends of the tube are uncovered or open, the musical instrument is said to contain an open-end air column.

COMPARING PITCHES

White Tubes – C 261 Hz 32.77 cm

Red - D 293 Hz 29.20 cm

Orange – E 329 Hz 26.01 cm

Yellow – F 349 Hz 24.55 cm

Green – G 391 Hz 21.87 cm

Blue – A 440 Hz 19.48 cm

Purple – B 493 Hz 17.36 cm

Black – C 523 Hz 16.38 cm

CAN WE PLAY A SONG WITHOUT INSTRUMENTS?

•Green Green Orange Green Blue Green Orange Orange Red Orange Red Green Green Orange Green Blue Green Orange Red Orange Yellow Orange Red White

•Orange Orange Orange Orange Orange Orange Orange Green White Red Orange Yellow Yellow Yellow Yellow Yellow Orange Orange Orange Orange Red Red Orange Red Green

•Green Blue Green Orange Black Blue Green Green Blue Green Blue Green Black Purple Green Yellow Orange Purple Blue Green Green Blue Green Blue Green Blue Green

WHY ARE THERE DIFFERENT PITCHES?

• The pitches change by either increasing the speed or the wavelength or in this case, the wavelengths may be varied by having tubes of differing lengths

• The higher pitch the sound the higher the frequency is. The lower the pitch the further away the wave length will be

• In a sound wave, the points of interference are called nodes

• The points of constructive interference is called the antinodes