reflection at an angle normal ray of light, or “ray” of sound at an angle to reflector virtual...
TRANSCRIPT
WAVE PHENOMENA
Reflection at an Angle
Normal
Ray of light, or “ray” of sound at an angle to reflector
Virtual Ray
Incident angle
reflected angle
i
r
i r
mirror
Think about this next time you play pool
Normal is drawn perpendicular to boundary
Refraction: bending of a wavefront at a boundary between two media, due to the change in velocity
Refraction
water
air
air
water
2
1Incoming wave
Slower velocity
Helpful Analogy: Marching Band
Firm Ground
Muddy Mess
Helpful Analogy: wheel on an axel
Firm Ground
Muddy Mess
DiffractionIf a sound wave hits a door opening, the sound will bend/spread
d
Spreading will be the most for…
Small opening relative to the wavelength.
So… smaller the opening , the morediffaction and the longer thewavelength the more diffraction.
Diffraction
d
• Larger barrier with smaller gaps relative to the wavelength.
• So… larger the barrier = smaller gaps, = more diffaction and again, the longer the
• wavelength the more diffraction.
Spreading will be the most for…
http://rt210.sl.psu.edu/phys_anim/waves/indexer_waves.html
http://paws.kettering.edu/~drussell/Demos/superposition/superposition.html
INTERFERENCE OF WAVESThe principle of superposition may be applied to waves whenever two (or more) waves are travelling through the same medium at the same time. The waves pass through each other without being disturbed.
Constructive interference: Point where two waves meet in phase to produce a wave of larger amplitude.
Destructive interference: Point where two waves meet out of phase in order to produce waves of smaller amplitude.