Physics

Problem

A wooden wall of area

15\,\text{m}^2

and thickness

0.040\,\text{m}

separates indoor air at

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

from outdoor air at

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

. The wood’s thermal conductivity is

0.12\,\text{W}\!\big/\!(\text{m}\cdot\text{K})

. If the temperature difference remains constant for

10

hours, what total amount of energy (to the nearest kilowatt-hour) is conducted through the wall? a)

15\text{ kWh}

5\text{ kWh}

9\text{ kWh}

90\text{ kWh}