difficult problem, need URGENT help A small pond has a layer of ice 1cm thick floating on its surface. (a) If the air temperature is −10C, find the rate in cm per hour at which ice is added to the layer. The density of ice is 0.917g/cm3 and its thermal conductivity is 0.592 W/mK. (b) How long does it take for a 20cm layer to build up? I think this problem requires the use of integrals. I dont know how to do that. I dont understand this problem AT ALL, so please help me out here.