Light and Color for the Middle School
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Light and Color for the Middle School By Greg Corder
description
Light and Color for the Middle School. By Greg Corder. TOC. Reflection and mirrors Refraction and lenses Applications of lenses and mirrors Color: light, pigments, and wavelength Diffraction Interference Light the electromagnetic wave Photoelectric effect - PowerPoint PPT Presentation
Transcript of Light and Color for the Middle School
Light and Color for the Middle School
By Greg Corder
TOC1. Reflection and mirrors2. Refraction and lenses3. Applications of lenses and mirrors4. Color: light, pigments, and wavelength5. Diffraction6. Interference7. Light the electromagnetic wave8. Photoelectric effect9. Nature of light: particle, wave, or both?
The Law of Reflection
Flat surfaces reflect best.
Curved Mirrors
• Concave mirrors converge light.
• Convex mirrors diverge light.
Concave MirrorLight converges. This means that it comes together.
Also, the image is flipped past the focal point.
Convex MirrorsLight diverges. This means that light spreads
out.
Curved Lenses
• Convex lenses converge light. The image is flipped past the focal point.
• Concave lenses diverge light.
Refractions causes light to bend.
The shape of the lens determines how the
light behaves.
Applications of lenses and mirrors
Periscope
Color
Dispersion…
Color separates using a prism because different colors have different wavelengths.
Red light bends the least and purple light bends the most.
Color depends on Wavelength of Light.
Colored lights combine to appear white.
Colored lights add to become white.Why then do paints add
to become black?
Answer: paints are pigments.
Pigments are chemicals which arecapable of absorbing one
or more frequency of white light.
Behaviors of light
Diffraction – a wave bends around an objectLight is a wave!
Light through a small slit.
Interference: light is a wave!
Polarized light is a
wave!
The Electromagnetic Spectrum
•
Maxwell - (c. 1864) light is an EM wave
The photoelectric effect: light is a particle!
The puzzle of intensity vs. energy
Einstein - (1905)–The duality theory of light–Light has a dual nature: light is both a
particle and wave
Sources:http://www.glenbrook.k12.il.us/gbssci/phys/Class/BBoard.htmlhttp://www.mhhe.com/tilleryTillery, Physical Science.http://cougar.slvhs.slv.k12.ca.us/~pboomer/physicslectures/secondsemester/telescopes/refracting.jpg
