Chapter 13

Light and Reflection

Light and Reflection

• Characteristics of light• Color and polarization• Flat mirrors• Curved mirrors

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primary

Additive – Mixing Light

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secondary

secondary

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primary

Subtractive – Mixing Pigments

ColorColor depends on the incident light and the reflected light

Explain why an object appears to be black

PracticeA lens for a spotlight is coated so that it does not transmit yellow light. If the light source is white, what color is the spotlight?

A house is painted with pigments that reflect red and blue light but absorb all other colors. What color does the house appear to be when it is illuminated by white light? What color does it appear to be under red light?

Electromagnetic Spectrum

electromagnetic wave = a wave that consists of oscillating electric and magnetic fields, which radiate outward from the source at the speed of light

Speed of EM Waves / Speed of Light

Illuminance

* Illuminance decreases as the square of the distance from the source

Polarization

Light can be polarized by…

1) Reflection

2) Scattering