Springs in suspension system of automobiles are made of steel rods heated and wound into coils while ductile. Consider steel rods (rho = 7832 kg/m^3, cp = 434 J/kg*K, and k 5 63.9 W/m*K) with diameter of 2.5 cm and length of 1.27 m. The steel rods are heated in an oven with a uniform convection heat transfer coefficient of 20 W/m^2*K. The steel rods were heated from an initial temperature of 20°C to the desired temperature of 450°C before being wound into coils.
A) Determine the ambient temperature in the oven, if the steel rods were to be heated to the desired temperature within 10 minutes.