Problem 1: The concrete slab of a basement is 11 m long, 8 m wide, and 0.20 m thick. During the winter, temperatures are nominally 17C and 10C at the top and bottom surfaces, respectively. a) If the concrete has a thermal conductivity of 1.4 W/m K, what is the rate of heat loss through the slab? If the basement is heated by a gas furnace operating at an efficiency of n = 0.90 and natural gas is priced at Cgas = $0.02/MJ, what is the daily cost of the heat loss? b) Radon contained in the soil beneath the basement slab is at a concentration of 5-10-17 kg/m. The radon concentration at the top of the concrete slab is 3. 10-17 kg/m. If the diffusion constant of radon in concrete is 8. 10-8 m/s, what is the mass flux of radon through the slab into the basement?