Transcript No Slide Title

Wave Interactions
Reflection
return of a wave when it
reaches a boundary of a medium
2 Types of Reflection:
Fixed Boundary:
the reflected wave is
inverted when it reflects
from a more dense medium
Free Boundary:
the reflected wave is
not inverted when it reflects
from a less dense medium
Reflection: Free vs. Fixed boundary
Refraction
•bending of a wave passing
from one medium into another
•Wave changes speed
For refraction to occur, the wave
must change speed and must enter
the new medium at an angle.
Refraction: Why waves always
go into the shore
Diffraction
the spreading of a wave
around a barrier or
through an opening
Island vs. Pillar
Diffraction & Reflection
Interference
•Two or more waves passing through
the same location at the same time.
•Also called: superposition
Superposition Principle
The total displacement due to
interference is the sum of the
displacements of the individual waves
Types of Interference
Constructive
results in a larger amplitude
Destructive
results in a smaller amplitude
Chapter 14 Section 3
Wave Interference Video
Interference Application
• Destructive interference used for our benefit
• Noise Cancellation Technology
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Cars
Headphones
Dentist Drills
Factories
Resonance
Resonance: Large amplitude waves caused
when the frequency of an applied force is
equal to the natural frequency of an object.
Video Examples:
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Wine Glass
Rice
Ruben's Tube
Tesla Coils & More Tesla Coils
Suspension Bridge with Harmonics
Washington Tacoma Bridge & Real Explanation
Doppler Effect
the change in frequency due to the relative
motion of the wave source and the observer
The observed frequency is higher when the
source and observer are getting closer.
The observed frequency is lower when the
source and observer are getting farther away.
Click here and here
to run simulations of the Doppler Effect.
The Doppler Effect
can be evident for
ALL types of waves –
including light,
sound, water, etc…
Big Bang TheoryDoppler Effect