Heat Transfer A blacksmith wants to forge a 30 cm long metal bar. The initial temperature of the bar is at 1100oC. The surrounding air temperature is 23oC. He is wondering if he could get prediction on the time required and the region that is ready for hammering. To help the blacksmith, you've been asked to solve the case of 1-D unsteady heat conduction and you end up with the following general solution: (Material: Pyrolytic graphite; Thermal diffusivity: 1220 mm²/s) Where Fourier number FO = a.