heat flow. Q5: A long 20 cm diameter cylindrical shaft made of stainless steel 304 comes out of an oven at a uniform temperature of 600°C. The shaft is then allowed to cool slowly in an environment chamber at 200°C with an average heat transfer coefficient of h= 80 W/m².°C. Determine the temperature at the center of the shaft 45 min after the start of the cooling process. Also, determine the heat transfer per unit length of the shaft during this time period? The properties of stainless steel 304 at room temperature are k= 14.9 W/m.ºC, p=7900 kg/m³, Cp= 477 J/kg.ºC, and a= 3.95x10-6 m²/s.