Light• Objects can absorb
light, reflect light, and allow light to pass through them.
• The type of matter in an object determines the amount of light it absorbs, reflects, and transmits.
Opaque
• Objects that are opaque only absorbs and reflects light – no light passes through it.
• My walls are opaque as is this beehive.
Transparent• Translucent materials
transmit almost all of the light that strikes them.
Translucent
• Translucent objects allow some light to pass through them but you can not see through them perfectly.
• Curtains and frosted glass are translucent.
Law of Reflection
• The Law of Reflection states that whatever angle the light wave strikes a surface, the light wave will be reflected at that same angle.
Answer
• Rough surfaces like brick walls…..cause diffuse reflection which is when the uneven surface causes incoming parallel light waves to be reflected in many different directions.
Refraction
• Refraction is caused by a change in the speed of the wave when it passes from one material (medium) to another.
Index of Refraction
• A property of the material that indicates how much it reduces the speed of light (how much it makes the light bend).
• If Index of Refraction is a big number, the more the light is slowed down…
• Eyeglasses, binoculars, cameras, and microscopes use refraction.
Prisms
• The triangular prism refracts the light twice (once when it enters and again when it leaves the prism.)
• Because the longer wavelengths of light are refracted less than the shorter wavelengths, red light is bent the least and the colors seem to separate out.
Rainbows
• Rain drops also refract light just like prisms.
• The refraction of the different wavelengths can cause white light from the sun to separate into different colors (red, orange, yellow, green, blue, indigo, and violet.)
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