B2) 30 pts. A GTAW operation is performed on low carbon steel, whose unit melting energy is 10.3 J/mm3 . The welding voltage is 22 volts and the current is 135 amps. The heat transfer factor is 0.7 (convection heat loss of 30%) and the melting factor is 0.65 (conduction heat loss of 35%). If filler metal wire of 3.5 mm diameter is added to the operation, the final weld bead is composed of 60% volume of filler and 40% volume base metal. If the travel speed in the operation is 5 mm/sec, determine: (a) The cross sectional area of the weld bead (b) The feed rate (mm/sec) at which the filler wire must be supplied