Question

A person wants to AB part of his image (see fig). Hi8s eye level is at 1.8 m above the ground. If he uses minimum size of mirror required for this, find the height of the lowest point of mirror above the ground.

• A. $2.4m$
• B. $7.4m$
• C. $1.4m$
• D. $3.4m$

Answer 1

The correct option is C $1.4m$

The minimum size of mirror should be half the total height

$=\frac{1.5-1}{2}=\frac{0.5}{2}$

Now, height above required

= (height from his eyes to A) / 2

$=\frac{1.8-1}{2}$ from level of A

$=\frac{0.8}{2}=0.4$ from level A

From ground $=0.4+1=1.4m$