In a manufacturing process, a long, coated plastic rod (p = 2200 kg/m3, c = 800 J/kg · K, k = 1 W/m · K) of diameter D = 20 mm is initially at a uniform tempera- ture of 25°C and is suddenly exposed to a cross flow of air at Too = 350°C and V = 50 m/s.
(a) How long will it take for the surface of the rod to reach 175°C, the temperature above which the special coating will cure?
(b) Generate a plot of the time to reach 175°C as a function of air velocity for 5 V 50 m/s.