A 2-mm-thick insulating coating (k =0.13 W/m-K) covers a 2-mm diameter electrical wire. The thermal contact resistance between them is RC =6x 10-4 m2K/W. The ambient air is at 25°C and has a convective heat transfer coefficient of 6 W/m2.K. If the temperature of the insulation cannot exceed 55°C, what is the maximum electric power that can be dissipated per unit length, in W/m? Find the corresponding surface temperature of the wire, in °C. d = i W/m