A long 10 cm × 20 cm rectangular cross bar k = 63.9 W/m·K and α = 18.8 × 10-6m2 was heated...

A long 10 cm × 20 cm rectangular cross bar k = 63.9 W/m·K and α = 18.8 × 10-6m2 was heated to an initial temperature of 450°C. The steel bar is heated to cool in a room with a temperature of 25°C and Co s allowed to transfer coefficient of 25 W/m2·K. The bottom surface of the bar is insulated while the other surfaces are exposed of the, exposed to convection. With a uniform nodal spacing of 5 cm, use SS-T CONDUCT (or other) software with explicit method, determine the duration required to cool the center of the bar to 100°C. Answer:12.000 s Fundamentals of Engineering (FE) Exam Problems

FIGURE P 5- 141