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Days of the week (always go to 1 st hour every day). Monday Guided Study after 2 nd hour Tuesday 1 st 25 minutes is Quiet Study Wednesday Advisory after 2 nd hour Thursday 1 st 25 minutes ReAdvisory Friday Guided Study after 2 nd hour.
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Days of the week(always go to 1st hour every day) • Monday Guided Study after 2ndhour • Tuesday 1st 25 minutes is Quiet Study • Wednesday Advisory after 2nd hour • Thursday 1st 25 minutes ReAdvisory • Friday Guided Study after 2nd hour
Class Notes..9.14.11. equation sheet,& polarization.Handout : equation sheetsHAND IN : Camera Obscura Lab late 1 dayif you started late, ask for a book…Hand in syllabus signatures and safety signature Wednesday: Notes, con’t worksheet pkt, equation sheet Thursday: Notes Colors and Review Friday: DUE:Test, notebook, equation sheet, both signatures Monday: Test returned and Notes on plane mirrors Tuesday: Homework if test <90%
Why Is the Harvest Moon Big and Red? • The Harvest Moon is the full moon nearest the date of the Autumnal Equinox. Orbiting Earth at a shallow angle to the horizon this time of year, the moon rises at around sunset for several days in a row. • Over the course of these days, the seamless transition from sunlight to moonlight provides farmers with additional time to bring crops in — and at just the right time of year for the harvest. • But the Harvest Moon provides a treat for non-farmers, too: Hanging low in the sky, it sometimes appears deep yellow or orange or even a vibrant red.
Why Is the Harvest Moon Big and Red? • Shortly after the Harvest Moon rises, light from it passes sideways through more atmosphere than does moonlight coming from overhead. Atmospheric particles tend to scatter moonlight's bluish components more than its reddish components, which are allowed to penetrate through to your eye. The moon thus appears redder the more atmosphere it passes through. Its color is most dramatic on nights when the atmosphere is especially muggy or hazy.
A low-hanging moon also appears larger than a high-flying one • This is a trick of the brain known variously as the moon illusion, or Ponzo illusion, which has been observed since ancient times but still has no generally accepted explanation. • One possible cause of the moon illusion is that we're used to seeing clouds just a few miles above us, while we know that clouds on the horizon can be hundreds of miles distant. We might therefore perceive an object on the horizon as farther away no matter what it is, and because the moon on the horizon is the same size as it normally is overhead, we perceive it as being much larger.
UN-Polarized Light • Light from an incandescent source is un-polarized since it is produced by radiating emission from many electrons in the heated tungsten wire and there is no preferred direction along which to produce their electric field.
Polarization • So how can light be polarized?
Light through a polarizing filter can be polarized • The part of the light oscillating the “wrong” direction is “cut off”
Only light oscillating the same direction as the filter will be allowed through. If the light is already polarized, it can get through a matching filter but will be blocked by a filter at 90 degrees
Why Choose Polarized Sunglasseslight reflecting off most shiny surfaces is polarized
Polaroid sunglasses. • You are sitting upright on the beach near a lake on a sunny day, wearing Polaroid sunglasses. When you lay down on your side, facing the lake, the sunglasses don't work as well as they did while you were sitting upright. Why not?
DEMONSTRATE: polarizing filters to observe polarization effects • You should notice that one filter reduces the intensity of the light. A second can cut it out completely, if correctly oriented. None of the light gets through Part of the light gets through All light gets through
Equation Sheets • # prongs from front equation sheet with the tape on top • Cut in the tape over the hole in the equation sheet protector. • Then Through the Graph paper sheet (graph paper on top • Name and other information on the graph sheet and the top of the first page of the equation sheet • Read directions on the graph sheet
Magnification Equationpage 1, space 1 Units None m m m m Symbol M di do hiho description Magnification Distance to image Distance to object Height of image Height of object Conditions for use Camera obscura or pinhole cameras Equation M = di = hi do ho
Velocity or speed equationpage 1, space 2 Equation • V=d/t • or d=vt Speed of light 3 x 108 m/s Units m/s m s Symbol V d t description Velocity or speed Distance time Conditions for use To find average speed or velocity, distance or time