00:01
So someone steps into a room and he walks in between two mirrors, one where he's two meters apart from it and the other where he's four meters apart.
00:11
So he's between these two mirrors and the question asks us, what is the distance that he has between the first close, the first three closest images on the left, almost left mirror right here? so we're only going to consider images formed on the left side here.
00:33
And we're going to find the distance from this person to those three images.
00:37
And we're going to use what we know about flat mirrors in this case to find those distances.
00:43
So let's just take it simple.
00:45
For the first part, i'm going to use blue on this side and red on the right -hand side.
00:50
This is our left.
00:54
This is our right.
00:57
On the left -hand side, you have your object.
00:59
This is the person here, and he's two meters away from this flat mirror.
01:02
So we know that if you are two meters away from your flat mirror here, the image is also going to be two meters away from the mirror on the virtual side, on the back side of the mirror.
01:31
Okay.
01:32
And for this, i'll try to make this clear.
01:35
This is going to be our object on the left side.
01:43
I'll do object l1 because this is our first object.
01:46
On the left side and this is going to be our first image on the left side so i'll say i l1 and so the distance between o l1 and il1 here is four so that's going to be the distance between the first image and the object here the first object is always going to be our person so we're always going to find the distance between our images il1 il2 il3 and ol1 which is our object so i'll just say that the distance is 4 meters since you have the image 2 meters away from the mirror and then your object 2 meters away from the mirror.
02:30
So it's a total of 4 meters.
02:32
Now, you also have to consider the left side on the right side.
02:39
The right hand side, it gives us an object distance of 4 meters.
02:53
I'll use this as object r1 and image r1.
03:09
And we know that this distance is 4 meters and so this distance is also 4 meters.
03:22
Now this image, this image is only in the back here.
03:28
This image because of what's happening with the virtual rays, it comes out and it appears that rays are emanating from this image.
03:41
And so the light rays from this mirror that reflect come back to this mirror.
03:48
Come back and it produces a second image because now we have an object that appears to be behind this mirror and it's going to produce a second image on this side and so we're just going to be looking for the images on this side of the mirror so what is our second image well we're going to have to take our first right image and make that our new object and that is a distance of 4 plus 4 plus 2 away from this mirror.
04:30
So it's a total of 4 plus 4 plus 2, which is 10.
04:38
That is our second object.
04:47
And i'm just going to put in parentheses, i .r .1...