Question

What is the heat flux (in W/m²) through the slab of 10cm thick if temperature drop across the slab is 40°C and the thermal conductivity of slab is 35 W/m.°C.?

Answer 1

$\phi _q=-k\frac{dT(x)}{dx}\\ \phi _q=-35*\frac{40}{\frac{10}{100}}\\ \phi _q=-14000W/m²\\ \phi _q=14000W/m²$