Reflection in a plane mirror (2)

[TheDevilvivek]

in concave, plane and convex mirror the ray of light do not pass through the mirror it refletc then how image is formed in the mirror.

[Cyberphysics]

@TheDevilvivek Images are either real or virtual.... virtual ones are formed by our brains when diverging rays enter our eyes. The brain calculates that they come from a point and tell us that the point of the image is there.

[Cyberphysics]

@TheDevilvivek If you look at the diagram on the webpage I directed to you that is what the diagram shows. I cannot help you as I cannot see your problem. The page shows diagrams for all of the positions.Look at the webpage: cyberphysics.co.uk/topics/ligh­t/concave_mirror_construct.htm

[Cyberphysics]

@TheDevilvivek You seem very confused - I suggest you talk this out with a physics teacher who has the equipment to show you practically what is going on.. These diagrams do not show how a full image is formed they show how the image of ONE POINT on the object is formed. See info on images in a mirror - lateral inversion.

[Cyberphysics]

:)

[ThePunkis23]

Im so smart right now~ altou i knew that all before viewed this epizoda of tis winderfull series now i feel more knowledgeable

[NOCOMMENT3176]

what is the angle of the two rays from the object point? is it anything or a fixed angle?

[Cyberphysics]

@NOCOMMENT3176 The angle could be anything. In reality there are millions of 'light rays' coming from the object - the diagram just shows the path of two of them. Just choose two which illustrate what happens - the examiner often gives you the rays you need to continue to find an image point.

[psycholeaks]

Finally I would like to add that contrary to popular belief, the image is NOT reversed RIGHT to LEFT. (Refer back to the translucent piece of paper concept comment). The image is reversed FRONT to BACK. Looking in the mirror, the image of my nose is closer than my ears. If I am facing North, my image is facing South. But if I raise my eastern hand, the eastern hand of my image, replicated exactly for a plane mirror, waves back at me. NOT my western hand. My eastern hand is not laterally flipped.

[Cyberphysics]

Good point - but I teach so that students get ALL of the marks on offer and to do that they must describe the image in a mirror as virtual, erect, as far behind the mirror as the object is in front, the same size as the object and laterally inverted... and that is what I teach them. who won't be confused by them.12 year olds have enough to worry about and exam script markers are not flexible...

[Cyberphysics]

Your discussion I may well have with Y13 students as I sometimes discuss my disagreements with naming and conventions - but for those wanting to get top grades so that they CAN look at physics from a non-prescription standpoint I read the mantra of the exam boards... (which can differ from board to board... we do AQA). For the mark they need to say the image is laterally (sideways) inverted (the other way round).

[psycholeaks]

And this is only how I view it for ease of comprehension. What works for me may not work for others.

[psycholeaks]

And nothing is actually "in" the mirror. It is only a surface. That is not possible. No light exists behind or in the mirror.The eye is decieved into thinking a point light source is coming from the reflected image in the mirror when we know intuitively that is not actually happening. Hence a virtual image. The eye only traces back the original lightsource that is reflected off the mirror...forming an image. You of course already knew this but did not offer that up for discussion. Keep in touch.

[Cyberphysics]

If you look at my site you will see that discussion of virtual and real images are there - this vid clip saves class time - they draw a ray diagram to a high standard for homework instead of me losing valuable lab time for it!

These vid clips are tiny snippets of a BIG site and tiny sections of my delivery of the subject at various levels...

[psycholeaks]

To your reply I didn't mean on the the mirror.I meant in the mirror exactly the same distance "behind" the mirror that it is in front of it. I was not trying to be awkward either. I was giving clarification for an offered situation. It is a mere trick on the eye. Nothing is being laterally inverted. A point is simply replicated in the mirror a distance behind the mirror as it is in front of it. A cube would look exactly the same. Image creation about a principle axis is more important.

[Cyberphysics]

My first vid clip deals with the as far behind as in front point - they also do an experiment to verify that.

[psycholeaks]

This is not exactly true. A plane mirror doesn't "flip" anything. If a word is written on a translucent piece of paper and held up to the mirror you can read the word just fine on the mirror, unless of course you write the word backwards...then you will simply read it backwards...the mirror will not "flip" the word so that it becomes legible. It is simply a trick to the eye. It is only latererally "flipped" when taken from the perspective of sideview. Poor video.

[Cyberphysics]

Write a word on a piece of translucent paper - now flip it over and look at the back of it - you have a laterally inverted version of what was on the front. A reflection of such a sheet in a mirror does not seem laterally inverted to you because you are seeing the 'normal' text in the mirror - but you are 'holding up the laterally inverted side of the message to the mirror (the back of your sheet is the object facing the mirror and that is already laterally inverted)>hope that is helpful!

[ToRiHale]

Hallo keep up the good videos and website. but I'm still stuck on colour 8P is very confused!!!

[ArtistIreland]

very good! :)