Answer
(a) $1.69m$
(b) $80.3m$
Work Step by Step
(a) We know that the sight line needs to cover a vertical distance of $19.6m-1.6m=18.0m$
and the sight line needs to cover a horizontal distance of $95m+2(0.50m)=96m$
Now the required height is given as
$h_i=19.6m-1.8.0m(\frac{95+0.5m}{96m})=1.69m$
(b) We know that the short segment of the sight line, in a horizontal distance of $0.50m$, covers a vertical distance of $(1.694m+0.32m)-1.6m=0.414m$
Now the total vertical distance covered by both segments of the sight line is given as
$h_2=(0.414m)(\frac{96m}{0.5m})=79.5m$
Thus, the highest point on the building the person can see with the mirror held at the height found in part(a) is $79.5m+1.6m=80.3m$
