wave behavior l.
Skip this Video
Loading SlideShow in 5 Seconds..
Wave Behavior PowerPoint Presentation
Download Presentation
Wave Behavior

Loading in 2 Seconds...

play fullscreen
1 / 22

Wave Behavior - PowerPoint PPT Presentation

  • Uploaded on

Wave Behavior. Another McGourty-Rideout Production. The Physics of Waves. All waves follow the laws of physics no matter what type Waves can be reflected, refracted, diffracted, absorbed, scattered and experience interference . Reflection.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Wave Behavior' - jacob

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
wave behavior

Wave Behavior

Another McGourty-Rideout Production

the physics of waves
The Physics of Waves
  • All waves follow the laws of physics no matter what type
  • Waves can be reflected, refracted, diffracted, absorbed, scattered and experience interference
  • Reflection happens when a wave bounces off an obstacle.

Specular reflection: smooth surface

    • Angle of incidence = angle of reflection

Diffuse reflection: rough surface

    • Reflection in all directions because angle of incidence varies over the surface due to its roughness
law of reflection
Law of Reflection

angle of incidence= angle of reflection

  • An echo - example of a reflection 
  • Radar uses this principle to determine the size, characteristics of, and distance to an object 
  • Occurs as waves move from one medium into another or within a medium, like air, that varies  in density or temperature
  • Waves bend toward the normal when they move from a less optically dense medium (faster) to a more optically dense medium (slower)
  • Waves bend away from the normal when the opposite is true
snell s law of refraction
Snell’s Law of Refraction
  • Angles are measured with respect to the normal
index of refraction
Index of Refraction

n = c / v

  • nair =1.0003
  • nwater = 1.33
  • nvacuum = 1.00
  • Can you explain why “n” is a naked number? Can it ever be less than 1?
index of refraction redux
Index of Refraction Redux


ε = electric permittivity

μ = magnetic permeability

These describe how the material interacts with electric and magnetic fields

atmospheric refraction
Atmospheric Refraction
  • Causes gradual curve of light from stars and sun
  • Makes sun visible 2-3 minutes before sunrise and after sunset

The index of refraction of real materials actually depends on the frequency of the light being bent.

Dispersion is the explanation for rainbows:

Each color has its own frequency 

Each gets slowed down differently 

Each comes out at a different angle

  • Waves that have longer wavelengths, or lower frequencies, diffract better than high frequency waves
  • Diffraction patterns are determined by both the size of the opening and the wavelength
  • Absorption happens when the medium has the ability to absorb the energy of the wave
  • When the wave is absorbed, its energy is transferred to the medium and the wave is gone
  • Gradual absorption as the wave penetrates the medium is called “attenuation”
  • Absorption of only specific frequencies will leave “gaps” in the continuing wave spectrum called “spectral absorption lines”
  • Absorption at the quantum level happens when an individual photon has the exact energy that corresponds to an energy gap between two energy states of the medium
  • The type of energy gap corresponds directly to the frequency of the photon
  • If the photon is absorbed and then re-emitted immediately, it is said to be scattered
  • How the light is scattered is dependent on the frequency of the light and the size of the particle it is scattering from
  • Some of the energy of the light is absorbed by the scatterer and so the re-emitted light has a little less energy
  • If the photon has a longer wavelength than the size of the scattering particle, it is called Rayleigh scattering
  • In Rayleigh scattering the very long wavelength light is hardly scattered at all but the shorter wavelength is much more strongly scattered
  • Since blue light is much ‘shorter’ than red, it gets more scattered by the molecules in the air: therefore the sky is blue!
  • When two or more waves come together, they “superimpose” or add together
  • The total amplitude is simply the sum (positive & negative!) of all the individual amplitudes
  • The extremes of what can happen are called constructive interference and destructive interference
constructive and destructive algebraic addition






(180° out of phase)

Constructive and Destructive Algebraic Addition

Partially Constructive

(somewhat out of phase)


(in phase)

Non-coherent signals


interference fringes
Interference Fringes
  • Interference fringes are a series of bright and dark bands
  • Sometimes straight, sometimes circular, sometimes more complicated
young s double slit experiment
Young’s Double Slit Experiment
  • Light diffracting through 2 slits produces fringes on a screen
  • Bright fringes are areas of constructive interference
  • Dark fringes are areas of destructive interference