reflection, refraction, diffraction, interference...2013/04/10 · objectives wwbat… describe and...
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Reflection, Refraction, Diffraction, Interference
Objectives WWBAT…
Describe and differentiate between reflection, refraction, diffraction, and interference
Describe the change in speed or wavelength for a refracted wave based on a diagram
Predict the shape of a wave formed by interference
The 4 Types of Wave Behaviors Reflection
Refraction
Diffraction
Interference
Reflection When a wave hits a surface and rebounds off that
surface in a different direction
Frequency Wavelength Speed
Stays the same Stays the same Stays the same
Refraction A wave changes media and changes speed
Causes waves to “bend”
Material a wave is moving through
i.e. air, water, glass, etc.
Frequency Wavelength Speed
Stays the same Decrease/Increase Decrease/Increase
Refraction How can we tell which medium a wave moves faster
in?
Wavelength is longer in deep water
Wave moves faster in deep water
Refraction How can we tell which medium a wave moves faster
in?
If the wave moves slower, it will bend away from the boundary ( (towards the perpendicular).
If the wave moves faster, it will bend towards the boundary.
Refraction Example: Does the wave move faster in air or in glass?
Refraction You Try: Does the wave travel faster in air or in water?
Air
Water
Diffraction Wave passes through a slit or around a boundary
Creates a “ripple” effect
Frequency Wavelength Speed
Stays the same Stays the same Stays the same
Interference Two or more waves collide and their amplitudes add
together or cancel out
Interference Will they add or cancel?
Interference Will they add or cancel?
Interference Will they add or cancel?
Amplitudes will add if both crests align
Amplitudes will cancel if their crests and troughs align
Interference Example: Determine the resultant waveform from the
interference of Wave 1 and Wave 2.
Interference YouTry: Determine the resultant waveform from the
interference of Wave P and Wave Q.
Interference CONNECTION ALERT!
For those of you in precalculus studying sequences and series, Fourier series are a VERY important way of describing complex waveforms (like electrical signals) as a sum of interfering sinusoids