One end of a cylindrical iron rod of length $1.00 \mathrm{m}$ and of radius $1.30 \mathrm{cm}$ is placed in the blacksmith's fire and reaches a temperature of $327^{\circ} \mathrm{C}$. If the other end of the rod is being held in your hand $\left(37^{\circ} \mathrm{C}\right),$ what is the rate of heat flow along the rod? The thermal conductivity of iron varies with temperature, but an average value between the two temperatures is $67.5 \mathrm{W} /(\mathrm{m} \cdot \mathrm{K})$.