Reflection and mirrors

 SC.7.P.10.2  Observe and explain that light can be reflected, refracted, and/or absorbed.  La  The student will organize information to show understanding (e.g. Representing main ideas through charting)  Page 324

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Diffuse Reflection

 Definition:  A reflection occurs when parallel rays of light hit a smooth surface.  Rays:  Visible light waves that are represented as straight lines.  All rays reflect at the same angle because of the smooth surface.

Image definition: An image is a copy of the object formed by reflected or refracted rays of light

 Definition:  A diffuse reflection occurs when parallel rays of light hit an uneven surface.  Each light ray obeys the law of reflection but because the surface is uneven the rays reflect at different angles which makes the image unclean or distorted.  Most objects have diffuse reflections or images even if they appear flat like paper or blades of grass.

 Definition:  A flat sheet of glass that had a smooth, silver-colored coating on one side.  The coating is smooth and regular and a virtual image is formed.  Virtual images  Definition: An image that forms where light “seems” to come from.  Images that seem real but do not really exist, such things “inside” the mirror.  Virtual images produced by plane mirrors are upright and the same size as an object.

 Real Image –  Image is made from “real” light rays that converge (meet) at a real focal point so the image is REAL  Can be projected onto a screen because light actually passes through the point where the image appears  Always inverted (upside down)  Trip and Flip concept!!!

 Virtual Image–  “Not Real” because it cannot be projected  Image only seems to be there!  Virtual gaming!!!

object image It is possible to see images in mirrors.

 Definition:  A mirror with a surface that curves inward like the inside of a bowl.  Optical Axis:  An imaginary line that divides a mirror in half (like the equator on the earth)  Concave mirrors create a focal point (on the optical axis) where the rays that are parallel to the optical axis meet.

 Curves inward  May be real or virtual image View kacleaveland's map Taken in a place with no name (See more photos or videos here)more photos or videos here "Have you ever approached a giant concave mirror? See your upside-down image suspended in mid-air. Walk through the image to see a new reflection, right-side-up and greatly magnified. In the background you see reflected a room full of visitors enjoying other

REMEMBER THIS?  Real images:  Definition: forms when light rays actually meet.  Real images are formed past the focal point and are upside down.  Real images can be smaller, bigger, or the same size as the actual object.  Image past the object = larger real image  Image in front of the object = smaller real image  Virtual images = upright and larger

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 Definition:  A mirror with a surface that curves outward  The reflected rays spread out after they reflect off the mirror so the focal point actually appears to form “inside” the mirror.  Image formed = virtual and smaller than the actual object.

 Curves outward  Reduces images  Virtual images  Use: Rear view mirrors, store security… CAUTION! Objects are closer than they appear!

Always:  Virtual, reduced, upright image