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Starter. You are outside and hear a sonic boom. This means that the jet making the boom……… just broke the sound barrier. had broken the sound barrier sometime earlier. …..neither of these. Wave Types. Wave Types. Wave Types. Transverse : Water Waves , Light Waves,
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Starter You are outside and hear a sonic boom. This means that the jet making the boom……… just broke the sound barrier. had broken the sound barrier sometime earlier. …..neither of these.
Wave Types Transverse : Water Waves , Light Waves, Waves on a guitar string Longitudinal: Sound Waves , Pulse on a slinky Note: Polarization occurs only in transverse waves. You can’t polarize a sound wave, but you can polarize light.
Doppler Effect When the source of a wave is moving with respect to you, the frequency you receive will be different from the frequency at the source. http://galileoandeinstein.physics.virginia.edu/more_stuff/flashlets/doppler.htm http://www.youtube.com/watch?v=h4OnBYrbCjY
How to calculate the frequencyreceived. Put the receiver to the left of the source, then the signs of all velocities are positive to the right, negative to the left. fR= fS V = speed of the wave VR = speed of the receiver VS = speed of the source fs = frequency of the source fR = frequency received
Example A car moving at 30 m/s sounds a horn at 440 Hz. What frequency do you hear if it is: Moving towards you. fR= fS VR = 0, Vs = -30m/s, V = 343 m/s, fs = 440Hz fR= fS , fR= 440 = 482 HZ
Example A car moving at 30 m/s sounds a horn at 440 Hz. What frequency do you hear if it is: Moving away from you. fR= fS VR = 0, Vs = +30m/s, V = 343 m/s, fs = 440Hz fR= fS , fR= 440 = 404 HZ Listen
Polarization This is a polarized light wave. If you saw it coming straight towards you, the E field vector would look like this:
Polarization Most light is unpolarized. If you saw it coming straight towards you, the E field vector would look like this:
How to Polarize Light Reflection from a smooth surface polarizes light:
Blocking Polarized Light NOTHING
Diffraction of Waves Diffraction Around Obstacles If the wave length is large compared to the obstacle, it bends around it. If the wavelength is small compared to the obstacle, a shadow is left.
Diffraction of Waves Diffraction Through Openings If the opening is large compared to the wavelength, it wont spread much. If the opening is small compared to the wavelength, the wave spreads a lot.
Forced Resonance Resonance is an increase in amplitude do to a material vibrating at the same frequency as a sound wave.