$***$MYHEAT LOSS $($Q$)$ IS WRONG AND IDK WHY I TRIED $943\mathrm{.}36$ AND THAT IS WRONG AS WELL$***$ Hot air at atmospheric pressure and $75\backslash$deg C enters a $25-$m$-$long uninsulated square duct of cross section $0\mathrm{.}15$m$\backslash$times $0\mathrm{.}15$m that passes

through the attic of a house at a rate of $0\mathrm{.}2($m$^(3))/($s$).$ The duct is observed to be nearly isothermal at $70\backslash$deg C$.$ Determine the exit temperature

of the air and the rate of heat loss from the duct to the airspace in the attic. The properties of air at a bulk mean temperature of $75\backslash$deg C

are $\backslash$rho $=1\mathrm{.}014$k$($g$)/($m$^(3)),$k$=0\mathrm{.}02917($W$)/($m$)*\backslash$deg C$,$v$=2\mathrm{.}046\backslash$times $10^(-5)($m$^(2))/($s$),$c$\_($p$)=1007\mathrm{.}5($J$)/($k$)$g$*\backslash$deg C$,$ and Pr$=0\mathrm{.}7166.$ Is this a good assumption?

The exit temperature of the air is

$70\mathrm{.}38\backslash$deg C$.$

The rate of heat loss from the duct to the airspace in the attic is