Long aluminum wires of diameter 3 mm (ρ = 2702 kg/m3 , cp = 0.896 kJ/kg·K, k = 236 W/m·K,...

Long aluminum wires of diameter 3 mm (ρ = 2702 kg/m3 , cp = 0.896 kJ/kg·K, k = 236 W/m·K, and α = 9.75 × 10–5 m2 /s) are extruded at a temperature of 350°C and exposed to atmospheric air at 30°C with a heat transfer coefficient of 35 W/m2 ·K. (a) Determine how long it will take for the wire temperature to drop to 50°C. (b) If the wire is extruded at a velocity of 10 m/min, determine how far the

wire travels after extrusion by the time its temperature drops to50°C. What change in the cooling process would you propose to shorten this distance? (c) Assuming the aluminum wire leaves the extrusion room at 50°C, determine the rate of heat transfer from the wire to the extrusion room.