1. The problem statement, all variables and given/known data A steel cylinder of radius 7.0 cm and length 4.0 cm is placed in end-to-end thermal contact with a copper cylinder of the same dimensions. If the free ends of the two cylinders are maintained at constant temperatures of 85°C (steel) and 20°C (copper), how much heat will flow through the cylinders in 19 min? 2. Relevant equations Q = (kAtdeltaT)/L Q=heat k for steel=66.9 k for copper=395 A=area t=time T=temperature L=length 3. The attempt at a solution x=temperature in the middle of the cylinders I set heat transferred through the steel part of the cylinder equal to the heat transferred through the copper part of the cylinder. (66.9)(85-x) = (395)(x-20) x=29.4 then using that value, i solved for Q. Q=((66.9)(.0154)(85-29.4)(1140))/.04 so Q=1.6E6 J BUT the answer is Q=1.17E6 J where'd i go wrong?