A resistance spot welding operations is performed on two pieces of 1.5 mm thick sheet steel using 12000 A for a 0.2 sec duration. The electrodes are 7 mm in diameter at the contacting surfaces, resistance is assumed to be 0.0001 ohm, and the resulting weld nugget is a sphere of a 6 mm diameter The unit melting energy for the metal U-12.03/mm cube. What portion of the heat generated was used to form the weld nugget and what portion was dissipated in to the work metal,electrodes and surrounding air. 2022 portion 02 82 Mark16-88