# Periscope reflection, but it seems backwards

1. Apr 4, 2013

### heatherro92

This is the question and the answer choices. I thought it would be mirror one creates E and mirror 2 creates F, but It's not.... help?

File size:
4.1 KB
Views:
48
2. Apr 4, 2013

### heatherro92

Then I thought the answer might be C and G, but that's also incorrect, I'm just not sure what to do!

3. Apr 5, 2013

### PeterO

Extend the mirrors 1, so that you can find a point perpendicularly behind the mirror, and the same distance behind as well - as always happens with a flat mirror.

Now extend mirror 2 and repeat the above step for the final image position.

4. Apr 5, 2013

### CWatters

Perhaps remember that mirrors don't magnify an image so the image can't appear closer than the distance a light ray takes from the object to the eye via the mirrors.

5. Apr 5, 2013

### heatherro92

Then I would think B would be the image from 1, but then there is no image from 2... I mean D is perpendicular, but it is further away then the distance from the object to the original mirror

6. Apr 5, 2013

### haruspex

As PeterO says, extend mirror 1 (in this case, up and to the right). If the object is at O and the image is at point X then you should find that the mirror perpendicularly bisects OX. That is not true of OB.

7. Apr 6, 2013

### PeterO

You got B by extending the line from the object past the end of the existing mirror 1. That line is not perpendicular to the mirror.

I said extend mirror 1 - especially up to the right - then draw a line from the object that forms a right angle with the mirror.

Images in plane mirrors are DIRECTLY behind the mirror - so the line joining an object and and image is always perpendicular to the mirror.

8. Apr 6, 2013

### CWatters

heatherro92 - Try this experiment. Go to the bathroom and stand facing the mirror. Turn 45 degrees to the right. Does the image in the mirror stay in position A or move to position B ?

File size:
4 KB
Views:
48