Physics

Problem

A house owner wants the heat loss through a flat roof of area

30\,\text{m}^2

not to exceed

600\,\text{W}

when the indoor temperature is

25\,^{\circ}\!\text{C}

higher than the outdoor temperature. Determine the minimum thickness of mineral wool insulation (thermal conductivity

0.04\,\text{W}\,\text{m}^{-1}\,\text{K}^{-1}

) that must be laid on the roof.