Approximately how long should it take 8.2 kgkg of ice at 0∘C∘C to melt when it is placed in a carefully sealed Styrofoam ice chest of dimensions 25 cmcm ×× 35 cmcm ×× 55 cmcm whose walls are 1.2 cmcm thick? Assume that the conductivity of Styrofoam is double that of air and that the outside temperature is 28 ∘C∘C.