2. [5 pts] Two steel sheets (of 9.9 J/mm specific melting energy), each 8 mm thick, are resistance seam welded at 250 amps, 220 volts, and 18% efficiency. The desired weld cross sectional area (measured perpendicular to the weld seam) is 20 mm within a total welding time of 20 seconds or less. What is the largest possible weld length (in mm) that can be achieved?