A cube of aluminum 10 cm on each side is initially at a temperature of 300°C and is immersed in a fluid at 100°C. The heat-transfer coefficient is 900 W/ m2 · °C. The transient of a cube is the product of transient of three infinite plates. Calculate first the temperature at the center of one face after 1 min, then determine the temperature at the center of any of the six faces after one minute