A metal bar is used to conduct heat.When the temperature at one end is 100°C and at the other is 20°C,heat is transferred at a rate of 16 J/s.If the temperature of the hotter end is reduced to 60°C,what will be the rate of heat transfer?
A) 4 J/s
B) 8 J/s
C) 9 J/s
D) 12 J/s

Question

Quizplus · Accepted Answer

The rate of heat transfer in a metal bar is directly proportional to the temperature difference. Using the formula Q/t = k*A*(Thot-Tcold)/L, where Q/t is the rate of heat transfer, k is the thermal conductivity of the metal, A is the cross-sectional area of the bar, L is the length of the bar, and Thot and Tcold are the temperatures of the hot and cold ends, respectively. Since all other factors are constant, we can set up a proportion: (Thot1 - Tcold)/(Thot2 - Tcold) = Q1/Q2. Substituting the given values, we get (100-20)/(60-20) = 16/Q2, solving for Q2, we get Q2 = 8 J/s. Therefore, the rate of heat transfer when the temperature of the hotter end is reduced to 60°C is 8 J/s.

A Metal Bar Is Used to Conduct Heat