Heat through conical section

Heat flows through a conical section of wall, whose diameter is given

by the formula: $D=ax.$

Given:

$a=0\mathrm{.}25$

$x_1=50mm$

$x_2=250mm$

$T_1=400K$

$T_2=600K$

$1$ point

Area of the section at $x_1[m^2]$

$2$

$1$ point

Area of the section at $x_2[m^2]$

$3$

$5$ points

Assuming a k value of $3\mathrm{.}40[\frac{W}{m}.K],$ calculate the heat flow $k\frac{J}{s}$

through the section $($ignore the effects of convection$).$ The hot and

cold temperatures are $580$ K and $399$ K respectively.

$4$

$1$ point

If convection were included in the question, heat transfer would have

been

Higher

Lower

The same

Impossible to tell without more information