$($Q$9)$ Calculate the minimum fire size at floor level capable of activating fixed

temperature heat detectors $($rated at $70C)$ in a large exhibition hall having the

room height of $10$ m high. Assume that the ceiling is flat and that the detectors

are spaced at $5$ m centre to centre. Ambient temperature, $T_{}=20C$ and

$g=9\mathrm{.}81\frac{m}{s^2}.$ Calculate fire sizes, Q $,$ for each of the following locations:

$($a$)$ the fire is directly above the detector;

$($b$)$ at the center of the enclosure;

$($c$)$ close to one wall;

$($d$)$ in a corner