Question

A glass Louvre pane 0.4 cm thick has an area 2×10^4 cm^2. On a very cold day the temperature difference between the inside and the outside surfaces of the pane is 25 degree Celsius determine the heat flow through the window

Answer 1

As per the question,

Thickness of the pane=0.4cm

Area$=2×10^4 cm^2$

Temperature difference between the pan $(\Delta T)=25^\circ C$

Let the conductivity of the material $=K$

Hence, rate of the heat flow $\frac{dQ}{dt}=\frac{KAd\theta}{l}$

Now, substituting the values,

$\Rightarrow \dfrac{dQ}{dt}=\frac{K\times 25\times2\times 10^6 cm^2}{0.4cm}=125\times K \times 10^6 J/sec$