00:01
In the given problem, there is a plain mirror.
00:10
This is the plain mirror, which is silver polished from right side.
00:19
Now there is a point in front of this mirror a, which is at a distance of 10 cm in front of this plain mirror.
00:36
And vertically it is at a depth of 5 cm if we look it from the top edge of this mirror.
00:51
Then the rays starting from this point a reflects from this mirror and reaches at a point b, which is directly opposite to the bottom edge of this mirror at a distance of 15 centimeter and the distance the vertical depth of this point from the top edge of the mirror is 15 centimeter or we can see the height of this mirror will be 15 centimeter now actually what will have happen, the rays will start moving from point a towards the mirror, then will be reflected from this mirror, and finally will reach at point b after suffering a reflection at this point c.
01:54
In such a manner that here this is the angle of incidence i, and this is the angle of reflection are we complete these right angled triangles here.
02:13
So these are two right angle triangles.
02:16
We consider this point to be d and let it be e.
02:21
So we have to find how far below the top edge does the ray strike the mirror means we have to find the position of point c below the top edge of this mirror.
02:38
So first of all, using the laws of reflection, we know angle i is equal to angle r, hence we can say 10 will also be equal to 10r...