Light and Optics Review for Final Exam

1. Describe the difference between transparent, translucent and opaque Transparent materials allow light to be transmitted straight through and so we can see images clearly, translucent materials allow light through but it is scattered so that images are blurry and opaque materials totally block light from getting through 2. What is a ray of light? A ray is a straight line that represents the path of light 3. What is evidence that light travels in straight lines? Formation of shadows 4. If the man in the picture moved closer to the wall, what would happen to his shadow? It would get smaller and less fuzzy

5. Describe chemiluminescence, bioluminescence, incandescence and fluorescence Chemiluminescence is light that is produced from a chemical reaction Bioluminescence is light that is produced from a chemical reaction but it is in a living (bio) organism Incandescence is the formation of light by heating something up to a very high temperature Fluorescence is the formation of light by the absorption of ultraviolet light 6. What causes refraction? Refraction is caused by the speeding up or slowing down of light as it moves into a substance with a different density 7. Describe what causes this pencil illusion This pencil illusion is caused by refraction or the bending of light as it moves through materials of different densities 8. During refraction, when light travels into a substance that is more dense, it bends __towards______(towards or away from) the normal. When light travels into a substance that is less dense, it bends __away from___ (towards or away from) the normal. 9. Draw the normal line on the pencil picture 10. Is the normal line parallel or perpendicular to the surface of the water? Normal line is perpendicular 11. What causes a mirage? A mirage is an illusion that happens when the brain tries to interpret what sensory information it is receiving from the eye. It interprets this information based on past experience or what it expects to happen 12. Draw a diagram of the eye and label each part.

13. Identify the camera parts that perform the same function as eye parts film- retina lens- lens ciliary body or aperture- musclepupil

diaphragm-iris lens cover-eyelid focussing ring-ciliary muscle protective glass-cornea 14. Draw a diagram of a far-sighted eyeball and show the position of the focal point

normal eye 15. Draw a diagram of a near- sighted eyeball and show the position of the focal point 16. Draw a simple diagram of a reflecting telescope and identify/label the parts

17. In reflection, the angle of incidence _____equals______(equals, is greater than or is less than) the angle of reflection 18. Describe the image you see in a convex mirror and lens mirror-made smaller, lens-larger 19. Describe the image you see in a concave mirror and lens mirror-magnified, lens-made smaller