Mirrors, Mirrors, Mirrors?

Question

Relative to the size of the mirror, what happens to the size of your own face as you look at it and move away from the mirror?

Question2: You are standing in front of the mirror looking at the reflection of the face of the person standing behind you. The person backs away from the mirror. Relative to the size of the mirror, what happens to the size of the reflection of their face (as measured by you on the surface on the mirror)

What is the minimum height of (length of mirror) of a plane (flat) mirror mounted vertically on a wal that would be required for a person to see his/her whole body when standing upright in front of the mirror?

Answer 1

The mirror always has to faces you should watch that movie and I fell you will find your answer.

Answer 2

Hi!

The answer for both questions 1 and 2 is same. The sizes of the faces, relative to the size of mirror, get smaller as you/the person moves away from it.

Question no. 3 is incomplete. Here the distance of the person standing in front of it is required. Because the minimum size of mirror, which is asked, changes relative to the distance of the person from the mirror.

For example, if the person is standing far from the mirror, the mirror length will have to be large and in case he stands closer to it, length decreases.

For an exact answer, draw ray diagrams taking a constant distance of the person from the mirror, and using some simple maths and some science, you will find out the answer.

Answer 3

1 and #2  Do you have a mirror at home?  Why not simply try this experiment and find out!

For #3, the bottom edge needs to be halfway between your eyes and bottom of your feet.  The top needs to be halfway between your eyes and top of head.  I think the answer they are looking for is probably "1/2 total height" which is not entirely correct.  

Note the other answerer said you need the distance to the mirror -- not true!  Draw the ray diagrams!  Both your eyes and your feet move farther away, and so required mirror size stays the same.  In real life, there is often some sort of vanity in front of the mirror -- in which case you would need to know the depth of the vanity and in that case you would need to know distance , as the vanity blocks part of the FOV.  But in the simple case -- person standing vertically, in front of a vertical mirror, size depends soley on height of your eyes (and height of the top of your head if you want to see your hair).