A modern cabin has a concrete floor that is 6.00 inches thick. A roaring fire keeps the interior of the cabin at 25.0 0C while the air temperature below the cabin is a chilly -2.00 0C (negative 2 celsius). How much heat (J) is lost through the concrete floor in 1 hr if the cabin floor measures 4.50 m by 6.50m to 3 sig fig?

Table 13.1 Thermal Conductivityes of Selected Materials Thermal Conductivity, k Substance [J/(s . m . Co)] Metals Aluminum 240 Brass 110 Copper 390 Iron 79 Lead 35 Silver 420 Steel (stainless) 14 Gases Air 0.0256 Hydrogen (H2) 0.180 Nitrogen (N2) 0.0258 Oxygen (02) 0.0265 Other Materials Asbestos 0.090 Body fat 0.20 Concrete 1.1 Diamond 2450 Glass 0.80 Goose down 0.025 Ice (0 .C) 2.2 Styrofoam 0.010 Water 0.60 Wood (oak) 0.15 Wool 0.040 Except as noted, the values pertain to temperatures near 20 .C