2007-02-01 09:01:54 · 8 answers · asked by jessika 4 in Science & Mathematics ➔ Physics
Depends on how big the person is, how close they are to the mirror and the type of mittor (plain, convex, concave etc)
If basically standing immediately in fron of the mirror and wish to be able to simply look forward and see rather than look "down into the mirror", and you are using a plain mirror, then it needs to be similar in size to yourself - like the vertical mirrirs on shops.
if you are standing 20 fet back from the mirror, you might be able to see the whole of yourself in a bit of mirror smaller than 12" square.
It would help if you had given the requirements - eg: clothing shop, bedroom dressing table etc
2007-02-01 09:08:07 · answer #1 · answered by Mark T 6 · 1⤊ 0⤋
Draw a ray diagram. Let the top of the mirror be equal to the height of the observer's eyes. Light coming from the observer's feet hits the bottom of the mirror, reflects back towards the person, and is seen by the observer. Because the angle of incidence equals the angle of reflection, the ray diagram looks like an isosoles triangle. A quick check will reveal that the mirror has to be 1/2 the height of the observer.
In looking at the other answers, I saw a couple of things that might lead you astray. Draw the ray diagram; you'll see that if the mirror is half the height of the observer, it doesn't matter how far away the observer stands or how big they are - assuming it's a flat mirror. Also, if it's less than half the observer's height, it doesn't matter how far away it is -- they'll never see their entire body. If the mirror is less than half the observer's height, then light from his feet will reflect at an angel too great to reach his eyes - it'll go off above his head.
2007-02-01 17:08:45 · answer #2 · answered by Grizzly B 3 · 3⤊ 0⤋
There are many factors that play into this equation. First: what is the shape and size of the mirror. Second: How far away is the mirror from the person? Third: What angle is the mirror at relative to the person, and or plane which is perpendicular to the person? Fourth: What is the size and shape of the person. Fourth: Is there any light and or are there, substances which can distort that light ( or block it) in the space shared by both the person and the mirror.
2007-02-01 17:32:31 · answer #3 · answered by Anonymous · 1⤊ 0⤋
The mirror can be of any size.....the important thing is where the person is from the mirror or the distance between that person and the mirror.....the further that person is the more detail the mirror will reflect the closer he is the less the detail.
2007-02-01 17:12:07 · answer #4 · answered by Maybe pex 1 · 1⤊ 0⤋
If it is a flat mirror, it doesn't matter how big the mirror is because if you are standing far enough away the whole image will appear.
2007-02-01 17:10:26 · answer #5 · answered by sangreal 4 · 1⤊ 0⤋
Any size, plain mirror must be standing vertically upright and, the smaller the mirror is, the further away the person must stand.
2007-02-07 12:21:29 · answer #6 · answered by Norrie 7 · 1⤊ 0⤋
More information please. Of course you need to know how big the person it.
Also, it depends on where the observer is and on the shape of the mirror and many other factors.
A tiny mirror right next to the observer's eye can see enormous things.
2007-02-01 17:07:39 · answer #7 · answered by Anonymous · 1⤊ 0⤋
WELL HOW BIG IS THE PERSON THEN YOU CAN ASK THAT QUESTION!!!!!!!!!!!!!
2007-02-01 17:05:19 · answer #8 · answered by tinkerbell23 1 · 1⤊ 0⤋