Water at 5°C is being used to cool apples from an initial temperature of 20° to 8°C. The water flow over the surface of the apple creates a convective heat-transfer coefficient of 10 W/(m²K). Assume the apple can be described as a sphere with an 8-cm diameter and the geometric center is to be reduced to 8°C. The apple properties include thermal conductivity of 0.4 W/(m K), specific heat of 3.8 kJ/(kg K), and density of 960 kg/m3. Determine the time that the apples must be exposed to the water.