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Light and Mirrors Review. True or False?. Black and white are colors of light. False, Black is not a color of light. It is a lack of light. However, black and white could both be a color of pigment. What color is produced when red and blue light are combined? Magenta
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True or False? • Black and white are colors of light. • False, Black is not a color of light. It is a lack of light. • However, black and white could both be a color of pigment.
What color is produced when red and blue light are combined? • Magenta • What color is produced when yellow and cyan pigments are combined? • Green
Color lists • Primary colors of light R, G, & B • Primary colors of pigment M, Y, & C • Secondary colors of light M, Y, & C • Secondary colors of pigment R, G, & B • Complimentary colors R & C, G & M, B & Y
A magnifying make-up mirror is held 4.0 cm from your face resulting in a magnification of 3.0 times. Determine the distance between the image of your face and the focal length of the mirror. di = -12 cm f = 6 cm Distance from f to di = 18 cm
What is the speed of light? • 3.0 x 108 m/sec. Think again…. • This is the speed of light in a vacuum. • Other medium could slow light down a little, a whole lot or even stop it all together. • Light is not just restricted to visible light.
Electromagnetic Spectrum • PRIVUX G.C. • Power, Radio, Infrared, Visible, Ultraviolet, X-ray, Gamma, Cosmic • Visible light = Roy G. Biv • Note: the capital letters are the primary colors
More E.M. spectrum • Cram the two spectrums together, make some small changes and you have the order: • Radio, • Microwave, • Infrared, • red, orange, yellow, green, blue, indigo, violet, • Ultraviolet, • X-ray, • Gamma
E.M spectrum summary • The wavelength of Radio waves are very long while the wavelength of X-rays are short. • This means that the frequency of Radio waves is very low while X-rays have a high frequency. • Waving frequently requires more energy. • X-rays have much more energy than Radio • What color has the greatest frequency? • violet
Two lights have equal luminance on a surface. One bulb has a luminous flux of 1750 lumens and is 1.5 meters away. The other has a luminous flux of 1000 lumens. How close is the second blub to the surface? • P1= 1750 lm • r1= 1.5 m r2= 1.134 m • P2= 1000 lm
Which cup is opaque? Blue = Opaque, Green = Translucent, Clear = Transparent
Is all light visible with the human eye? • Only a very small fraction of light can be seen by the human eye. Most “light” in the electromagnetic spectrum can is composed by waves either too large or too small for the eye to detect.
See other good calculation questions in appendix B! • Chapter 16 page 876 Chapter 17 page 877 • 1) 0.98 m 1) 29 degrees • 2) 460 lm 2) 77 degrees • 3) 140 lx 3) 35.0 degrees • 4) 650 nm 4) 11 cm • 5) 6.63 x 1014 Hz 5) -2.3 • 6) 6.29 x 106 m/sec 6) -8.1 cm 7) 0.3 8) 2 m 9) 0.33 m