5-79 Consider a 1000-W iron whose base plate is made of0.5-cm-thick aluminum alloy 2024-T6 (p =C, = 875 J/kg-°C). The base plate has a surface area of 0.03 m2.Initially, the

iron is in thermal equilibrium with the ambient air at 22°C. Assuming 90 percent of the heat generated in the resistance wires is transferred to the plate, determine the minimum time needed for the plate temperature to reach 200°C.