Estimate the time when the temperature at the geometric center of a 6 cm diameter apple held in 2`C water stream reaches 3oC. The initial uniform temperature of the apple is 15`C. The convective heat transfer coefficient in water surrounding the apple is 50 W/m2 `C. The properties of apple are thermal conductivity k = 0.355 W/m`C; specific heat Cp = 3.6 J/kg`C, and density = 820 kg/m3.