MUSICAL ACOUSTICS
WAVES
Science of Sound,
Chapter 3
WHAT IS A WAVE?
Waves are disturbances that transport energy
and information through a medium (but the
medium itself is not transported).
Waves can be longitudinal (e.g. sound waves)
or transverse (e.g. waves on a string or water
waves).
WAVE PROPERTIES:
•Reflection
•Refraction
•Interference
•Diffraction
•Doppler Shift
ttp://www.animations.physics.unsw.edu.
au/
//www.avnimations.physics.unsw.edu.a
Traveling wave on a
rope
Reflection of a pulse:
at a fixed end
at a free end
Mirror image of an
impulsive wave
approaching:
A plane mirror (left)
A corner mirror
(right)
REFLECTION OF AN IMPULSIVE WAVE
At a fixed end
At a free end
SUPERPOSITION OF WAVE PULSES
INTEFERENCE OF TWO
IDENTICAL WAVES ON
A STRING
At times t1 and t5 there
is constructive
interference;
at time t3 there is
destructive
interference.
Note that at points
marked N, the
displacement is always
zero; this represents a
STANDING WAVE
REFLECTION OF PRESSURE (SOUND) PULSE
SPEED OF SOUND IN IDEAL GAS
OCEAN WAVES
WHEN THE WAVE ENTERS SHALLOW WATER IT SLOWS DOWN AND ITS
HEIGHT INCREASES
DOPPLER EFFECT
REFLECTION – WATER WAVES
REFLECTION – SOUND WAVES
REFRACTION
REFRACTION
TWO MEDIUMS
REFRACTION THROUGH
A PRISM
ANGLE OF INCIDENCE
REFRACTION OF LIGHT
BY WATER
IMAGES FORMATION
BY LENSES
REFLECTION
REFRACTION
INTERFERENCE OF WAVES
FROM TWO IDENTICAL SOURCES
INTERFERENCE
OF WATER
WAVES
DIFFRACTION
OF WATER
WAVES BY A
SLIT
DIFFRACTION
DIFFRACTION
OF LIGHT
BY A PIN
DIFFRACTION
OF LIGHT BY
A SCREW
DIFFRACTION
OF LIGHT BY
A RAZOR
BLADE
DIFFRACTION
BY A SINGLE
SLIT
DIFFRACTION
DIFFRACTION OF WATER WAVES
DIFFRACTION OF LIGHT AND SOUND WAVES
SPECTRAL ENERGY DISTRIBUTION OF A WHITE LED
LED SPECTRAL RESPONSE CURVE