# Please i cannot find any help on this question so far

1. Apr 14, 2008

### bharp24

please... i cannot find any help on this question so far!!

A rod is initially at a uniform temperature of 0 degress celsius throughout. One end is kept at 0 degress celsius, and the other is brought into contact with a steam bath at 100degrees celsius. The surface of the rod is insulated so that heat can flow only lengthwise along the rod. The cross-sectional area of the rod is 2.50 cm^2 , its length is 120 cm, its thermal conductivity is 380 W/m * K, its density is 1.00 x 10^4 kg/m^3, and its specific heat capacity is 520 J/ kg * K. Consider a short cylindrical element of the rod 1.00 cm in length.

1.If the temperature gradient at the cooler end of this element is 140 deg C/m, how many joules of heat energy flow across this end per second?

2.If the average temperature of the element is increasing at the rate of 0.250 deg C/sec, what is the temperature gradient at the other end of the element?

I have gotten number 1 to be 13.3W and know it is correct, but really need help on number 2.

I have been trying to find what the average temperature gradient even is and am not successful. If anyone knows anything about how to do this problem, your posts would be greatly apprecitated!

Last edited: Apr 14, 2008