What is Light? Light is a kind of ______________________. Light travels in transverse waves. Speed of Light (c) = 3.00 x 10 8 m/s Speed of Light (c) = 3.00 x 10 8 m/s Electromagnetic Radiation

Electromagnetic Spectrum UV light (Ultraviolet Light) Sun, __________________, Black Lights. X - Rays Medical x-rays, airport security. Gamma Rays Sterilizing Equipment, ____________________. tanning beds cancer treatments

Radio waves Micro waves Infrared. Ultra- violet X- Rays Gamma Rays Visible Light Electromagnetic Spectrum

Radio Waves Radio Stations, 2-way radio,_______________, radar (navigation), listening devices (bugs) Microwaves Microwaves, ________________, speed radars, Television, Ovens Infrared Used by Police and Firemen to see inside buildings. remote controls Cellular Phones

Electromagnetic Spectrum Visible Spectrum – Light we can see Y R O Y G B I V Largest to Smallest Wavelength. Larger wavelength = Lower frequency = less energy Shorter wavelength = Higher frequency = more energy

Radio waves Micro waves Infrared. Ultra- violet X- Rays Gamma Rays High Frequency Long WavelengthShort Wavelength Visible Light Electromagnetic Spectrum Low Frequency Low energyHigh energy

Speed of Light Speed of Light (c) = 3.00 x 10 8 m/s Velocity of Light = (frequency)(wavelength) V = f λ 3.00 x 10 8 = f (400) f = 750,000 Hz Ex. If a light wave has a wavelength of 400 m, what is its frequency?

Transverse Waves Transverse Waves -_____________________________ _______________________________________________. Wave Propagation – ____________________________ _______________________________________________. energy moves perpendicular to the direction of the wave To make a wave (disturbance) that moves through a medium (water).

Polarization Polarize = _____________________. Uses? Uses? Polarized sunglasses reduce glare, 3D glasses, wireless communication is filtered light.

Vocabulary Transparent Objects: __________________________________________________. Translucent: __________________________________________________. Opaque: __________________________________________________. Question 1 Are clouds transparent or opaque to visible light? Question 2 Are clouds transparent or opaque to ultraviolet light? Answer: transparent Answer: opaque materials through which light can pass in straight lines materials that absorb some light and let some light pass materials that absorb light.