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Image Formation and Reflection

  1. Nov 10, 2011 #1

    san203

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    I have been having trouble with this for a long time

    1st - How and Why is a image formed ?

    2nd - If all objects reflect light why is the image not seen on all the objects

    Even walls reflect light but there is no image formation when light rays from an object reflect off an object and strike the Wall.
     
  2. jcsd
  3. Nov 10, 2011 #2
    1st: when you understand that, please let me know! Its not easy.
    2nd: image may not form on an object always.
    wall is too rugged to form image of all points of some object on a single plane, so that you could see the image.
    this will also help you in another way: all things reflect light but the percentage of light reflected depends on the angle of incidence: http://physics-animations.com/Physics/English/rays_txt.htm"
     
    Last edited by a moderator: Apr 26, 2017
  4. Nov 10, 2011 #3

    sophiecentaur

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    An image is something that you can see and identify in some way. You identify a part of an image by light entering your eye as if it came from an array of points that correspond (well or badly, depending on the 'quality') to an original (maybe not an actual) object. But light appears to be spreading out from those points.

    You see the surface of a gloss painted wall (or a dirty mirror) because some light is actually scattered by imperfections on the surface (diffuse reflection) and your eye / brain identify them as being on the surface. But you can also see reflected objects because a significant amount of the reflected light can be identified by your eye / brain as coming from other locations (called a coherent reflection) because light appears to be spreading out from identifiable points on their imagee.

    Images in a reflection are called Virtual, because the light doesn't actually originat in the points that you 'see' - it just looks as if it does. Many of the images in lenses are virtual because the light doesn't actually originate from a real array of points at all. There are conditions when the light coming from a lens (or concave mirrior) actually passes through a real location in space (a focus) and that's a real image. You could put a screen there and an image would actually form on the screen.
     
  5. Nov 12, 2011 #4

    san203

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    Thanks sophiecentaur for helping me again.I sat down and thought about it hard before visiting this thread again and had pretty much figured this out on my own but you confirmed my logic.

    BTW will i get to learn this better when i am older?
    I am in the 10th grade now.
     
  6. Nov 12, 2011 #5

    sophiecentaur

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    I am sure that, if you take the trouble to ask on forums like this one, you will do find. Good luck with your Science.
     
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