sound…5th grade (teach)
DESCRIPTION
Touches on some of the basic sound ideas at about the sixth grade level. Uses some home videos to demonstrate points.TRANSCRIPT
By Moira Whitehouse PhD
Must download/save to see the videos/animations
SOUND IS A FORM OF ENERGY CAUSED BY
SOMETHING VIBRATING.
SOUND IS A FORM OF ENERGY THAT YOU CAN HEAR
CAUSED BY SOMETHING VIBRATING
A FORM OF WHAT??
ENERGY
CAUSED BY WHAT??
VIBRATIONS
WATCH THE SALT BOUNCE AROUND AS THE SOUND WAVES FROM THE RADIO
CAUSE THE STRETCHED RUBBER TO VIBRATE.
YOU SAW THE STRETCHED RUBBER BOUNCED ABOUT
BY THE SOUND VIBRATIONS.
WE CALL THESE VIBRATIONS SOUND
WAVES.
WE HEAR THE SOUND, WE SEE THE THUMB NAIL PIANO TINES BEING PLUCKED BUT THE
VIBRATIONS ARE SO FAST THAT WE CAN NOT SEE
THEM.
NOW WE WILL SEE THAT THE SOUND COMING
FROM A TUNING FORK IS ACTUALLY CAUSED BY
VIBRATIONS.
SOUND VIBRATIONS, REMEMBER, ARE
ALSO CALLED SOUND WAVES
NEXT WE OBSERVE SOME CHIMES CHIMING BUT WE SEE NOTHING
VIBRATING.
WHAT IS VIBRATING INSIDE THOSE TUBES THAT MAKES THE “BELL- LIKE” SOUND?
THE ONLY THING IN THE TUBES WAS
AIR
IT MUST HAVE BEEN THE AIR VIBRATING
HERE WE STRIKE BOTTLES WITH
DIFFERENT AMOUNTS OF
WATER AND NOTE THE SOUND.
WAS THE AIR VIBRATING TO MAKE THIS SOUND, OR
WAS IT THE WATER?
IT WAS THE WATER. WE KNOW, BEAUSE THE JARS WITH LESS WATER MADE
THE HIGHER PITCHED SOUND.
AH, PITCHWHAT IS IT?
HIGH PITCH, LOW PITCH AND HOW LOUD A SOUND BECOMES, IS
DETERMINED BY SOUND WAVES
SOUND WAVELENGTH IS DETERMINED BY HOW FAST THE
SOURCE OF THE SOUND WAS VIBRATING.
THE MORE SOUND WAVES THAT PASS BY YOUR EAR
IN ONE SECOND THE HIGHER THE PITCH.
THE DISTANCE FROM ONE SOUND WAVE PEAK TO THE
NEXT IS THE WAVELENGTH OF A SOUND WAVE.
FAST VIBRATIONS GIVE SHORT WAVELENGTHS
MAKES HIGHER PITCH
SLOWER VIBRATIONS GIVE LONGER WAVELENGTHS
MAKES LOWER PITCH
HOW LOUD SOUND BECOMES IS
DETERMINED BY HOW MUCH ENERGY IS IN THE SOUND WAVE.
THE DISTANCE FROM CREST TO A CREST
OR FROM A CREST TO A TROUGH
SHOWS THE ENERGY IN A SOUND WAVE
THE LESS ENERGY
THE SOFTER OR QUIETER THE
SOUND
THE MORE ENERGY
THE LOUDER THE SOUND
MANY THINGS AFFECT PITCH.
ON A GUITAR FOR EXAMPLE, PITCH IS AFFECTED BY THE THICKNESS OF THE VIBRATING STRING.
STRING LENGTH ALSO
AFFECTS PITCH
AND HOW TIGHT THE STRING IS
AFFECTS PITCH.
IN THE NEXT LESSON WE WILL FIND OUT HOW
SOUND TRAVELS.