Answer
(a) $61.44m$
(b) increase
Work Step by Step
(a) We can determine the required vertical height as follows:
$H=\frac{h}{d}(D+d)+h$
We plug in the known values to obtain:
$H=(\frac{0.32m}{0.50m})(95m+0.50m)+0.32m$
$\implies H=61.44m$
(b) We know that $H=(D+d)\frac{h}{d}+h$
This simplifies to:
$\implies H=h(2+\frac{D}{d})$
Now, if we move the mirror closer to our eyes, the value of $d$ decreases and hence the vertical height of the building can be seen in the mirror at any time. Thus, $H$ will increase with an increasing ratio of $\frac{D}{d}$.