Question

The wall of house, 7m wide and 6m high is made from 0.3m thick brick with kT =0.6 W/m-K. The surface 

temperature on the inside of the wall is 16˚C and that on the outside is 6˚C and that on the outside is 6˚C. Find

the total heat loss per second through it.

Answer 1

$Q=k\frac{\Delta T}{\Delta x}At$

$A=7\cdot6=42\ (m^2)$

$t=1\ (s)$

$\Delta T=16-6=10\ (°C)$

$\Delta x=0.3\ (m)$

$k=0.6\ (W/(m\cdot K))$

$Q=0.6\cdot\frac{10}{0.3}\cdot42\cdot1=840\ (J)$ . Answer