Ch9_GreensteinJ

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=Notes 5/3=
 * Forced Vibrations
 * When one vibrating object causes another to vibrate with the same frequency
 * Natural frequency
 * Every object has its own rate of vibration depending on many characteristics (i.e. length, material, shape, etc.)
 * Resonance
 * When an object is forced to vibrate at its natural frequency
 * This causes amplification in the second object
 * Types of waves
 * Transverse
 * Look like sine waves
 * Energy travels perpendicular to particle vibration
 * Longitudinal (Pressure)
 * Look like | || ||| || | || ||| || |
 * Energy travels parallel to particle vibration
 * Classes of Waves
 * Mechanical
 * Must have a medium to travel through
 * Electromagnetic
 * Does not require a medium
 * EM- Electromagnetic waves (light, infrared, gamma...)
 * Created by accelerating charged particles
 * Wave
 * Crest
 * Maximum amplitude
 * Trough
 * Minimum amplitude
 * Wavelength
 * Distance from one point on a wave to the corresponding point on the next wave
 * Period
 * Time for one wavelength

=Notes 5/7=


 * Properties of waves
 * Reflection
 * When a wave bounces back
 * Echo, reverberation
 * Law of Reflection
 * Angle of incidence equals angle of reflection
 * Refraction
 * Bending of wave due to change in wave speed
 * Only when you change media
 * Going from fast (F) to slow (S), bend towards normal (T)[[image:http://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/Refraction_-_Huygens-Fresnel_principle.svg/300px-Refraction_-_Huygens-Fresnel_principle.svg.png caption="http://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/Refraction_-_Huygens-Fresnel_principle.svg/300px-Refraction_-_Huygens-Fresnel_principle.svg.png"]]
 * Going from slow (S) to fast (F), bends away from normal (A)
 * Diffraction
 * The spreading of a wave beyond an obstacle
 * [[image:http://www.smkbud4.edu.my/Data/sites/vschool/phy/wave/Diffraction-Water-Waves.gif caption="http://www.smkbud4.edu.my/Data/sites/vschool/phy/wave/Diffraction-Water-Waves.gif"]]
 * "Shadow"
 * No wave
 * Depends on wavelength and size of opening
 * Bigger opening, less diffraction
 * Bigger wavelength, more bending
 * Interference
 * When two waves overlap, the resultant displacement is the algebraic sum of the individual wave's separate amplitudes
 * The Principle of Superposition
 * Constructive interference
 * Increases net amplitude
 * "In phase"
 * Destructive interference
 * Decreases net amplitude
 * "Out of phase"
 * "Out of phase"

=Notes 5/9=


 * Standing waves
 * A pattern produced on a medium due to interference
 * Example of resonance
 * Nodes
 * Regions of 0 displacement