Electromagnetic Waves Spectrum Waves Electromagnetic waves Crest waves

Electromagnetic Waves & Spectrum

Waves �Electromagnetic waves. �Crest- waves are transverse top of wave. �Trough- bottom of wave. �Wavelength- can be measured as the distance from crest to crest or from trough to trough.

Electromagnetic Waves �Electromagnetic waves- are made up of electric and magnetic fields. �They are a result of particles vibrating back and forth. �Requires NO medium.

Electromagnetic Waves �Transfer of energy through EM waves is called radiation. �All EM waves travel through empty space at 300, 000 km/s.

Frequency �Frequency- the number of waves that pass in a given amount of time. �Frequency � 1 is measured in Hertz (Hz). Hz is equivalent to 1 cycle/second.

Frequency �A longer wavelength means a lower frequency, and a shorter wavelength means a higher frequency!

Electromagnetic Spectrum �Going from strongest to weakest � Gamma � X-Rays � Ultraviolet light � Visible light � Infrared � Microwaves � Radio waves

Gamma Rays • Kills cancer • Kills bacteria • Penetrates materials

X- Rays �Medical imaging

Ultraviolet light • Above violet • Sunburns • Kill bacteria • Produces Vitamin D

Visible light �ROY G BIV

Color wavelengths �Infrared – 10 cm �Red – 7. 5 cm �Orange – 6. 3 cm �Yellow – 5. 75 cm �Green – 5. 3 cm �Blue – 4. 5 cm �Indigo – 4. 3 cm �Violet – 4. 0 cm �Ultraviolet – 0. 3 cm

Infrared • Below red • Temperature • Night vision • T. V remotes

Microwaves ◦ Cell phones ◦ Satellites ◦ Radar

Radio Waves • Radio and T. V • A. M. (amplitude modulation) • F. M. (frequency modulation)

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