Waves

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Waves
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Electromagnetic Spectrum

• Range of electromagnetic radiation or light
• Amount of energy given off by atomic electrons
• Visible Light middle of spectrum
• ROY G BIV

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Electromagnetic Spectrum
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Waves

• Rhythmic disturbances that transmit
• Energy
• Information
• Waves are usually comprised of a
• higher-energy state followed by a
• lower-energy state
• of a medium or an energy field

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Two kinds of waves

• Classified by the motion of the medium compared
  to the motion of the wave
• ACTUAL MEDIUM PARTICLES DO NOT MOVE!!!

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Two Kinds of Waves

• Transverse (Sine) Waves
• Medium particles move at right angles to the wave
  direction
• Water waves, wind waves, EM waves (radio, light,
  X-Rays, etc.)

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Two kinds of waves

• Longitudinal (Compression) Waves
• Medium particles move in the same direction as
  the wave
• Sound waves, certain earthquake waves, springs

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Which kind of wave vibrates in the same direction
as the wave?

• Transverse Wave
• Longitudinal Wave
• Seismic Wave
• Big Kahuna Wave

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Which of these can be transmitted by a wave?

• Energy
• Information
• Particles
• None of these

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What name is given to the material through which
a wave travels?

• Water
• Air
• Steel
• Medium

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Which kind of wave vibrates at right angles to
the wave?

• Transverse Wave
• Longitudinal Wave
• Seismic Wave
• Big Kahuna Wave

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A wave is a

• Motion on the ocean
• Amber unit of grain
• Non-verbal good-bye signal
• Rhythmic disturbance

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Which of these is an example of Compression or
Longitudinal waves?

• Sound Waves
• Water Waves
• The Wave at Quest Field
• None of these

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Which of these is an example of Transverse waves?

• Sound Waves
• Cymbals
• Accordions
• Ultraviolet Light

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PARTS OF A TRANSVERSE WAVE
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Parts of a Transverse Wave

• The Normal or Rest Position
• Represents the undisturbed medium
• Crest
• Point representing the highest energy of the wave
• Trough
• Point representing the lowest energy of the wave

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Properties of a Transverse Wave

• Amplitude
• Distance from the normal or rest position to the
  crest or trough
• Height of the wave
• Represents the amount of energy in the wave
• Wavelength
• Distance from one point on the wave to the same
  point on the next wave
• Distance of ONE FULL CYCLE of the wave
• Frequency
• Number of waves that pass a point in a unit of
  time
• Measured in Hertz (Hz) for waves per second

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Parts of a Longitudinal Wave

• The Normal or Rest Position
• Represents the undisturbed medium
• Compression
• Area representing the highest energy of the wave
• Medium particles are pressed together, area of
  high energy
• Rarefaction
• Area representing the lowest energy of the wave
• Medium particles are far apart, area of low energy

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Properties of a Longitudinal Wave

• Amplitude
• How tightly compressed particles of the wave
  are
• Represents the amount of energy in the wave
• Wavelength
• Distance from one point on the wave to the same
  point on the next wave
• Distance of ONE FULL CYCLE of the wave
• Frequency
• Number of waves that pass a point in a unit of
  time
• Measured in Hertz (Hz) for waves per second

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Longitudinal Waves

• Areas where the lines are close together is the
  same as the CREST in a transverse wave.

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Wave is the WORD!

• Decibel unit of sound intensity
• Ultrasonic above 20,000 hertz
• Echolocation using reflected waves to judge the
  size, shape, or location of an object
• Supersonic faster than the speed of sound
• Vibration cause of sound

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What is the lowest energy area of a longitudinal
wave called?

• Compression
• Medium
• Wavelength
• Rarefaction

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What is the highest point of a transverse wave
called?

• Trough
• Amplitude
• Crest
• Rest

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What is the lowest point of a transverse wave
called?

• Trough
• Amplitude
• Crest
• Rest

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Which describes how often a wave point passes a
particular location?

• Compression
• Frequency
• Wavelength
• Amplitude

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What is the horizontal line that represents an
undisturbed medium?

• Trough
• Amplitude
• Crest
• Rest

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What is the highest energy area of a longitudinal
wave called?

• Compression
• Medium
• Wavelength
• Rarefaction

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Which of these represents the amount of energy in
a wave?

• Trough
• Amplitude
• Crest
• Rest

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What is the distance between one point of a wave
to the same point on the next wave?

• Compression
• Medium
• Wavelength
• Rarefaction

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Other Wave Properties

• Wavespeed
• Velocity of a wave
• Can depend on the medium
• Sound travels faster through dense mediums, radio
  waves cant penetrate rock
• Wavespeed wavelength x frequency
• ? ? x ƒ
• Wavespeed is usually in m/s
• when wavelength is in m
• and frequency is in Hz (1/s)

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More on Wavespeed

• All EM waves travel at the Speed of Light
• Symbol c
• Value 186,282.6 miles per second
• 299,792,458 m/s
• This is currently the fastest speed in the
  Universe

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• Watch for these conversions!
• 1m 100000000 nm (nanometers)
• 1nm 1.0 x 10-9 m
• Light vibrates in the nm and ångström ranges
• 1 m 1000000000 Å
• 1 Å 1.0 x 10-10 m