Heating mechanisms
In the problems in this section, clearly identify the system and objects in the environment that interact with the system. Label the work as WEnvironment on System, heating as QEnvironment to System, and the change in internal energy as ΔUint.
Insulating a house You insulate your house using insulation rated as R-12, which will conduct 1/12 Btu/h of thermal energy through each square foot of surface if there is a 1 °F temperature difference across the material (R-12 insulation is said to have a thermal resistance R of 12 h . ft2 . °F/Btu). The conduction rate through a material of area A, across which there is a temperature difference T2 - T1, is
H Conduction = (1/R2) (T2 - T1)
Tree leaf A tree leaf of mass of 0.80 g and specific heat of 3700 J/kg . °C absorbs energy from the sunlight at a rate of 2.8 J/s. If this energy is not removed from the leaf, how much does the temperature of the leaf change in 1 min? [Note: Do not be surprised if your answer is large. A leaf clearly needs other heat transfer mechanisms to control its temperature.]
We need at least 10 more requests to produce the solution.
0 / 10 have requested this problem solution
The more requests, the faster the answer.