Consider a 1000 W iron, whose base is made of aluminum alloy 2024-T6 (=2770 kg/m3 and cp=875 J/kg C) and 0.5 cm thick. That base has 0.03 m2 of surface. First, the iron is in thermal equilibrium with ambient air at 22C. Assuming that 90 percent of the heat generated in the resistance wires is transferred to the base, determine the minimum time required for the iron to reach 200C.