Alloy steel ball of 2 mm diameter heated to 800oC is quenched in a bath at 100oC. The material properties of the ball are K = 205 kJ/m hr K, ? rho= 7860 kg/m3, Cp = 0.45 kJ/kg K, h = 150 KJ/ hr m2 K. Determine (i) Temperature of ball after 10 second and (ii) Time for ball to cool to 400oC.