Intro to Electromagnetic Waves

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Intro to Electromagnetic Waves
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Electromagnetic Waves

• Transverse waves consisting of changing electric
  fields magnetic fields

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Structure of an Electromagnetic Wave
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Electromagnetic Waves

• Transverse waves consisting of changing electric
  fields magnetic fields
• EM waves transfer energy without the transfer of
  matter
• EM waves DO NOT need a medium to travel
• EM waves produced by charges (electrons)
  vibrating or accelerating

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Source of Electromagnetic Waves
As the electron moves around the nucleus, it
produces a changing electric field. This energy
is carried by an EM wave.
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Field Forces

• Certain forces have the ability to change the
  motion of other objects, even though there is no
  physical contact

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What are fields?

• Area around an object where it can change the
  motion of other objects (apply a force)
• Electric Field area where forces are exerted on
  charged particles (/- charges)
• Produced by other charges or changing magnetic
  fields
• Magnetic Field area where forces are exerted on
  magnets
• Produced by other magnets or changing electric
  fields

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Electromagnetic Radiation

• Transfer of energy by EM waves traveling through
  space or matter
• The amount of energy depends on the wavelength
  and frequency of the wave
• Not the amplitude, as was the case for mechanical
  waves

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Speed of Electromagnetic Waves

• Light travels (way) faster than sound
• Speed of Light in a vacuum 3.00?108 m/s
• 300000000 m/s or 186000 mi/sec

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Speed of Electromagnetic Waves

• Light travels faster than sound
• Speed of light measured by Albert Michelson
• Speed of Light in a vacuum 3.00?108 m/s
• 300000000 m/s or 186000 mi/sec
• All EM waves travel at the same speed even though
  they have different wavelengths frequencies

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Michelsons Experiment
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Electromagnetic Radiation

• All EM waves travel at the same speed
• They have different frequencies wavelengths
• The amount of energy each wave carries is
  directly related to the frequency
• Higher frequency more energy

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Electromagnetic Spectrum

• The full range of frequencies of EM radiation
• EM Spectrum includes
• Radio Waves, Infrared Waves, Visible Light,
  Ultraviolet Waves, X-rays, Gamma Rays

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Electromagnetic Spectrum