A copper sheet of thickness 2L= 2 mm has an initial temperature of Ti= 140°C. It is suddenly quenched in liquid water, resulting in boiling at its two surfaces. For boiling, Newton’s law of cooling is expressed as q ′′=h(Ts-Tsat), where Ts is the solid surface temperature and Tsat is the saturation temperature of the fluid (in this case Tsat= 100°C). The convection heat transfer coefficient may be expressed as h=1010W/m2⋅K3(T-Tsat)2. Determine the time needed for the sheet to reach a temperature of T= 102°C.