A 19-M² Thermopane Window Is Constructed by Using Two Layers of of Glass

A 1.9-m² Thermopane window is constructed by using two layers of glass 4.0 mm thick,separated by an air space of 5.0 mm.If the temperature difference is 25.0 °C from the inside of the house to the outside air,what is the rate of heat flow through this window? (Thermal conductivity for glass is 0.840 J/s⋅m⋅°C and for air 0.023 4 J/s⋅m⋅°C. )

A) 2 530 W
B) 426 W
C) 3 190 W
D) 210 W
E) 2 100