1I got the 1st one..thanks..
Yeah..2nd one is 7. How did we get that?
Q1) A man of height 2h stands in the middle of the room of length 6h. The height of the wall is 4h. What is the minimum length of a mirror to be placed on the wall in front of him so that he can see the entire wall behind him?
Q2) How many images will be formed if two adjacent walls and the ceiling of a rectangular room are silvered? The object is kept at the centre of the room
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10 Answers
62For the first question, try simple geometry..
Try to draw straight lines and see where the light from his eyes will go...
The quesiton is a question of similar triangles....
(is it?)
see the final image height is 4H
Now also the lenght from the mirror is k M let...
The distance to the mirror is 3h, while the distance of the image of the wall from the eye of the man (Including the reflected lenght) is equal to 9h
So the mirror required will be 1/3rd the height of the wall
So 4h/3 is the minimum lenght of the mirror.
1
1TAKING 2 PERPENDICULAR..MIRORS ATA TIME
CASE 1:NO. OF IMAGES FORMED=36090=4
SIMILARLY FOR THE OHTER _I_ PAIR,
CASE 2:NO. OF IMAGES FORMED=36090=4
TOTAL =8
1 IMAGE IS COMON TO BOTH
HENCE 8-1= 7
THIS IS THE METHOD I FOLOW...U MAY THINK OF OTHERS
1THE images formed by al da three pairs of perpendicular mirrors..will give som comon or coincident images