試題詳解

Density: 2300 kg/m³ 

Specific heat: 840 J/kg•℃

Coefficient of linear thermal expansion: 8.5 x 10^-6 (℃)^-1

Thermal conductivity: 0.80 W/(m•℃)
 A glass window pane is 2.7 m high, 2.4 m wide, and 2.0 mm thick. The temperature at the inner surface of the glass is 22℃ and at the outer surface 4.0℃. How much heat is lost each hour through the window under steady state conditions?
(A) 1.7 x 10⁵ J
(B) 1.7 x 10⁶ J
(C) 4.7 x 10⁷ J
(D) 1.7 x10⁸J
(E) 4.7 x 10⁹ J.