A single-phase, 500-kVA, 440/120-V transformer feeds service loads via bus duct with two bus bars, each 1/2 × 3 in. in cross section and spaced ½ in. apart. An electrical system study has concluded that the worst-case fault current in the bus is 30,000 A at the first peak. Determine the peak mechanical force between the bus bars that will cause defection and bending stress between the supports. Assume the bus bar shape factor K = 0.7.