Exercise 5: A plane mirror is hanging on a vertical wall; a boy $1.6 m$ tall wants to see both his feet and top of his head in the mirror when he is standing erect.
Assuming his eyes are $15 cm$ below the top of his head find
(i) The minimum height of the mirror.
(ii) Its distance from the floor.

Answer

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Answer

$Distance from the floor = 1.1625 m$

Steps

Step 1 ： $Let the minimum height of the mirror = h$

Step 2 ： $It forms 1 : 1 ratio of the image because mirror distance = object distance$

Step 3 ： $h = \frac{1.6 - 0.15}{2}$

Step 4 ： $h = 0.725 m$

Step 5 ： $Distance from the floor = \frac{1.6 + 0.725}{2}$

Step 6 ： $Distance from the floor = 1.1625 m$