Arod is initially at a uniform temperature of 0oC through out. One end is kept at 0oC, and the other is brought into contact with a steam bath at l00oC. The surface of the rod is insulated 80 that heat can flow only lengthwise along the rod. The cross-sectional area of
The rod is 2.50 cm2, its length is 120 cm, its thermal conductivity is 380 W/m. K, its density is 1.00 X 104 kg/m3, and its specific beat is 520 J I/kg . K. Consider a short cylindrical element of the rod 1.00 cm in length.
(a) If the temperature gradient at the cooler end of this element is 140 Co/in, how many joules of heat energy flow across this end per second?
(b) If the average temperature of the element is increasing at the rate of 0.250 Co Is, what is the temperature gradient at the other end of the element?