A 0.2-m-long and 25-mm-thick vertical plate (k =1.5 W/m∙K) separates the hot water from the cold air at 2°C. The plate surface exposed to the hot water has a temperature of 100°C, and the surface exposed to the cold air has an emissivity of 0.73. Determine the temperature of the plate surface exposed to the cold air (Ts,c).