1. The problem statement, all variables and given/known data A cubical styrofoam cooler 80cm on a side and 2.0 cm thick contains 2.0kg of ice at 0C. If it takes four hours for the ice to melt what is the outside temperature? K(st)=.02 w/m*K 2. Relevant equations H=-KA (ΔT/ΔX) (conductive heat flow) 3. The attempt at a solution Area: 6(a)^2= 6(.8)^2= 3.8m^2 Δx=.02m K(st)=.02 w/m*K H=-.02 w/m*K(3.8m^2) (ΔT/.02m) So I used the formula for the conductive heat flow, but I still have two unknowns. I know H is ΔQ/Δt, but I am asked for the time. I had two questions in regards to this problem: 1. for the area do I find the total surface area or just one side? 2. what temperature change ΔT should I set the ΔQ formula if I am assuming the ice is melting? Thanks for the help!