MECHANICAL MECHANICAL WAVESWAVES

WAVE WAVE PROPERTIESPROPERTIES

SOUND…“WHAT?”SOUND…“WHAT?”

SOUNDS OF MUSICSOUNDS OF MUSIC

MIXED BAGMIXED BAG

COOL VIBRATIONSCOOL VIBRATIONS

MECHANICAL WAVES

WAVE PROPERTIES

SOUND…

”WHAT?”

SOUNDS OF MUSIC

MIXED BAG COOL VIBRATIONS

MECHANICAL WAVESMECHANICAL WAVESREQUIRE THIS IN ORDERREQUIRE THIS IN ORDER

TO PROPOGATE TO PROPOGATE

THE TYPE OF WAVE THE TYPE OF WAVE THAT STARTS WITH A THAT STARTS WITH A

SINGLE DISTURBANCE.SINGLE DISTURBANCE.

A WAVE IN WHICH THE A WAVE IN WHICH THE PARTICLES OCILLATE PARTICLES OCILLATE

PARALLEL TO THE PARALLEL TO THE DIRECTION OF DIRECTION OF PROPOGATION.PROPOGATION.

THE DIRECTION THE THE DIRECTION THE RED DOT ON THE WAVE RED DOT ON THE WAVE

IS MOVINGIS MOVING

DOUBLING THE DOUBLING THE AMPLITUDE OF A WAVE AMPLITUDE OF A WAVE WILL HAVE THIS EFFECT WILL HAVE THIS EFFECT

ON ITS ENERGY ON ITS ENERGY

THE TIME IT TAKES FOR THE TIME IT TAKES FOR A WAVE TO COMPLETE A WAVE TO COMPLETE

ONE CYCLEONE CYCLE

THE FREQUENCY OF A THE FREQUENCY OF A WAVE WHOSE PERIOD WAVE WHOSE PERIOD

IS 2 s.IS 2 s.

A COLLISION BETWEEN A COLLISION BETWEEN TWO WAVES THAT TWO WAVES THAT

RESULTS IN A WAVE RESULTS IN A WAVE GREATER THAN ITS GREATER THAN ITS

COMPONENTSCOMPONENTS

THE EFFECT THAT THE EFFECT THAT DOUBLING THE DOUBLING THE

WAVELENGTH HAS ON WAVELENGTH HAS ON THE WAVE SPEEDTHE WAVE SPEED

THE FREQUENCY OF THE FREQUENCY OF THE WATER WAVE THE WATER WAVE

THE PERCEPTION OF THE PERCEPTION OF HOW HIGH OR LOW A HOW HIGH OR LOW A

SOUND APPEARS TO BESOUND APPEARS TO BE

A REFLECTED SOUND WAVEA REFLECTED SOUND WAVE

SOUNDS BELOW 20 HZ SOUNDS BELOW 20 HZ

THE SPEED OF SOUND THE SPEED OF SOUND IN AIR AT 25IN AIR AT 25ooCC

THE MINIMUM DISTANCE A THE MINIMUM DISTANCE A REFLECTIVE SURFACE REFLECTIVE SURFACE

MUST BE IN ORDER FOR MUST BE IN ORDER FOR YOU TO HEAR AN ECHO YOU TO HEAR AN ECHO ON A DAY WHEN IT IS ON A DAY WHEN IT IS

2020ooC.C.

THE TERM THAT THE TERM THAT DESCRIBES THE DESCRIBES THE QUALITY OF THE QUALITY OF THE

SOUND PRODUCED BY SOUND PRODUCED BY AN INSTRUMENTAN INSTRUMENT

THE TYPE OF WAVES THE TYPE OF WAVES PRODUCED IN WIND PRODUCED IN WIND

INSTRUMENTSINSTRUMENTS

THE WAVELENGTH OF THE WAVELENGTH OF THE FIRST HARMONIC THE FIRST HARMONIC

ON A 30 cm VIOLIN ON A 30 cm VIOLIN STRING STRING

THE FREQUENCY THE FREQUENCY EMITTED BY A PIANO EMITTED BY A PIANO

WHEN A TUNER USES A WHEN A TUNER USES A 440 Hz TUNING FORK 440 Hz TUNING FORK AND HEARS 2 BEATS AND HEARS 2 BEATS

PER SECONDPER SECOND

THE FREQUENCY OF THE 5THE FREQUENCY OF THE 5THTH HARMONIC IN A 1 m ORGAN PIPE HARMONIC IN A 1 m ORGAN PIPE

THAT IS OPEN AT BOTH ENDS THAT IS OPEN AT BOTH ENDS WHEN THE AIR WITHIN THE PIPE WHEN THE AIR WITHIN THE PIPE

IS 20IS 20ooCC

THE OBSERVED THE OBSERVED CHANGE IN CHANGE IN

FREQIUENCY DUE TO FREQIUENCY DUE TO THE MOTION OF A THE MOTION OF A

SOUND SOURCE OR SOUND SOURCE OR OBSERVEROBSERVER

WHEN THE FREQUENCY WHEN THE FREQUENCY OF A FORCE APPLIED TO OF A FORCE APPLIED TO

A SYSTEM MATCHES A SYSTEM MATCHES THE NATURAL THE NATURAL

FREQUENCY OF FREQUENCY OF VIBRATION OF A VIBRATION OF A

SYSTEMSYSTEM

THE WAVELENGTH OF THE WAVELENGTH OF THE SECOND THE SECOND

HARMONIC ON A HARMONIC ON A GUITAR STRING OF GUITAR STRING OF

LENGTH L.LENGTH L.

THE MAXIMUM THE MAXIMUM POSSIBLE AMPLITUDE POSSIBLE AMPLITUDE

OF A RESULTANT WAVE OF A RESULTANT WAVE IF WAVES OF 1.0m AND IF WAVES OF 1.0m AND

0.5m AMPLITUDES 0.5m AMPLITUDES INTERACTINTERACT

THE FREQUENCY BEING THE FREQUENCY BEING EMITTED BY THE CAR EMITTED BY THE CAR TRAVELING AT 32 m/s TRAVELING AT 32 m/s WHEN OBSERVER ‘A’ WHEN OBSERVER ‘A’

HEARS A 450 Hz PITCHHEARS A 450 Hz PITCH

BBAA

THE FREQUENCY AT THE FREQUENCY AT WHICH ALL OBJECTS WHICH ALL OBJECTS

VIBRATE WHEN VIBRATE WHEN DISTURBEDDISTURBED

A VIBRATION THAT A VIBRATION THAT CAUSES ANOTHER CAUSES ANOTHER

OBJECT TO VIBRATEOBJECT TO VIBRATE

THE PHENOMENON THE PHENOMENON EXHIBITED IN THE EXHIBITED IN THE

FOLLOWING VIDEO FOLLOWING VIDEO

THE WAVELENGTH OF THE WAVELENGTH OF AN 88 MHz LIGHT WAVE AN 88 MHz LIGHT WAVE IF THE SPEED OF LIGHT IF THE SPEED OF LIGHT

IS 3.0x10IS 3.0x1088 m/s m/s

THE LENGTH OF A THE LENGTH OF A GUITAR STRING WHICH GUITAR STRING WHICH VIBRATES AT A VIBRATES AT A FUNDAMENTAL FUNDAMENTAL FREQUENCY OF 845 Hz FREQUENCY OF 845 Hz IF THE VELOCITY OF IF THE VELOCITY OF WAVES ON THE STRING WAVES ON THE STRING IS 574 m/s IS 574 m/s

DOPPLER EFFECTDOPPLER EFFECT

THE SPEED OF A SOUNDTHE SPEED OF A SOUND SOURCE THAT EMITS A SOURCE THAT EMITS A

200 Hz PITCH IF AN 200 Hz PITCH IF AN OBSERVER HEARS A OBSERVER HEARS A

180 Hz PITCH ON A 25180 Hz PITCH ON A 25ooC C DAYDAY

ANS: 38.4 m/sANS: 38.4 m/s