A \(3.50-\mathrm{kg}\) block of iron initially at \(8.00 \times 10^{2} \mathrm{~K}\) is placed on top of a \(6.25 \mathrm{~kg}\) block of copper initially at \(4.00 \times 10^{2} \mathrm{~K}\). How much energy is transferred thermally from the iron to the copper as the two blocks come to thermal equilibrium? Assume the blocks are thermally insulated from their surroundings but not from each other and that they constitute a closed system.