A person puts an apple in a freezer at -15°C in order to cool it quickly to eat it cold, but forgets about it and when h
Posted: Fri Jul 08, 2022 6:08 am
A person puts an apple in a freezer at -15°C in order to cool itquickly to eat it cold, but forgets about it and when he goes totake it out it has started to freeze. Initially, the apple was at auniform temperature of 20°C and the surface heat transfercoefficient is 8 W/m2 °C. Visualizing the apple as a 9 cm diametersphere and taking its properties as ρ= 840 kg/m3, cp = 3.81kJ/kg°C, k = 0.418 W/m °C and α= 1.3 x10-7 m2/ s, determine howmuch time elapsed from the time the apple was placed in the freezerto the time it began to freeze.