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S.M.T
S.M.T
05:57
@JohnRennie Hii sir.
John Rennie
John Rennie
@S.M.T Hi :-)
S.M.T
S.M.T
user image
The Q.
John Rennie
John Rennie
Is E the height of the man's eyes?
S.M.T
S.M.T
AZ is man’s height , FL2= Height of mirror.
E is the point where man’s eye is located. No specific length for it.
John Rennie
John Rennie
The principle here is that for the man to see his feet a light ray from his feet must be able to reflect off the mirror and reach the man's eyes. Yes?
S.M.T
S.M.T
06:01
I want to confirm my answer. Height of mirror needed for the man to see = 1/2Hi +1/2HA
@JohnRennie Yes.
L1 to L2 is not needed & FB is not needed as the mirror.
Mirror needed = L1 to B.
John Rennie
John Rennie
The light ray has to hit the mirror at exactly half the distance between the man's feet and his eyes. Yes? I can draw a diagram to show why this is if you want.
S.M.T
S.M.T
@JohnRennie No sir. I am okay with that point. My Q is I have found the minimum size of mirror needed , what will be the maximum size of mirror needed ?
John Rennie
John Rennie
OK :-)
There is no maximum size.
S.M.T
S.M.T
@JohnRennie But the Q asks for max & min ?
Textbook says max = min size.
John Rennie
John Rennie
The man won't stop being able to see his whole reflection as you increase the size of the mirror.
S.M.T
S.M.T
06:05
@JohnRennie K.
@JohnRennie So , if mirror given in Q = FL2 , Can we say max needed = FL2 & Min = BL1
John Rennie
John Rennie
If you post a picture of that page from the textbook I can have a look at it in case it means something I have misunderstood.
S.M.T
S.M.T
@JohnRennie My sir gave this Q in class from his book of question bank. I don’t know which book is it exactly.
He wrote the answers & Q only.
John Rennie
John Rennie
Then there is no maximum size. The mirror could be infinitely large.
S.M.T
S.M.T
@JohnRennie K. Must be a misprint then. Thank you sir. All clear.
John Rennie
John Rennie
:-)

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