Consider an ice chest with the following dimensions: length 50 cm, width 40 cm, and height 30 cm, made of a 3 cm thick insulating material ( k 0.033 W/[m °C]). The chest is fi lled with 30 kg of ice at 0°C. The inner wall surface temperature of the ice chest is assumed to be constant at 0°C. The latent heat of fusion of ice is 333.2 kJ/kg. The outside wall surface temperature of the chest is assumed to remain constant at 25°C. How long would it take to completely melt the ice? Assume negligible heat transfer through the bottom surface.