Reflection and color, Refraction, Lenses and Prisms 15-3 and 4

Reflection of light Light ray- imaginary line in the direction of the light.

Rough surface reflection is called diffused reflection examples are wood, cloth, and skin Rough surfaces– the light ray is reflected in many directions

Reflection of light Smooth surfaces- the light ray is reflected in one direction. Angle of incident = angle of reflection- Law of Reflection

Mirrors Plane mirrors are flat surfaced, the image is right side up and same size but left and right are reversed. Image appears to be on the other side of the mirror- virtual image

Mirrors Concave mirrors- curve inward, reflect to the same point, produce a real image and are used in telescopes and flashlights

Mirrors Convex mirrors- curve outward, produce and image that is right side up and smaller can give distortion for distance, ex a cars rearview mirror

Seeing Colors You see the color that is reflected off the object all other colors are absorbed, white= all colors are reflected

Seeing Colors Black= all colors are absorbed Prisms – separate colors out by their wavelengths.

Seeing Colors Additive primary colors are red, green and blue and when combined can produce secondary colors yellow, cyan and Magenta

Seeing Colors Mix all primary colors and get white. Mix all secondary colors and get black

Refraction of light Bending of light due to a change in speed as the wave enters another medium- look at fig 29 pg 513

Refraction Causes an object to appear in a different position either closer or farther away Mirage- light is bent as it goes thru different temp of air.

Lenses Any transparent material that cause light to bend inward (converge) or bend outward (diverge). Can be used to magnify

How we see Dependant on lenses and refraction. Light enters the cornea, the pupil and hits the lens

How we see The lens bends the light so it can focus on the retina in the back of the eye. Light stimulates the rods and cones and sends a signal to the brain.