Question
chapter 13 problem 05
MESSAGE MY INSTRUCTOR FULL SCREEN PRINTER VERSION BACk ES Chapter 13, Problem 05 One end of an iron poker is placed in a fire where the temperature is 404 °C, and the other end is kept at a temperature of 24.3 °C. The poker is 0.661 m long and has a radus of 5.36 x 10-3 m. Ignoring the heat lost along the length of the poker, find the amount of heat conducted from one end of the poker to the other in 2.00 s. Take the thermal conductivit of iron to be 79 J/(s m Co). Number Use correct number of significant digits; the tolerance is +/-2% 1 Units By accessing this Question Assistance, you will learn while you earn points based on the Point Potential Policy set by your instructor. Question Attempts: 0 of 5 used SAVE FOR LATER SUBKIT ANSWE en/shared/assignment/test/aglistum?id=asn mt 1963684:N 10079 earch
Explanation / Answer
thermal conductivity Iron is 79 W/mK
power = K x T x A / thickness
Area = r² = (0.00536)² = 0.0000902 m²
P = 79 W/mK x (404–24.3) x (0.0000902 m²) / (.661m)
P = 4.09 watts or 4.09 J/s
Energy = power x time
4.09 J/s x 2s = 8.18 Joules.