If two objects are at different temperatures initially and then are allowed to c
ID: 1913233 • Letter: I
Question
If two objects are at different temperatures initially and then are allowed to come into equilibrium without exchanging energy with the outside world (outside of the two objects), the entropy of the system must increase. If heat is taken out of a container of ideal gas whle the volume remains constant, no work is done by the gas. If the temperature of a fixed mass of ideal gas increases, the internal energy must increase. The amount of energy used by the electrical motor in a heat pump must be greater than the amount of heat that it adds to the interior of a house. True or False for each statement above.Explanation / Answer
1) U = N/2 k T so True 2) W = P dV so if dV = 0 then W = 0 True 3) carnot heat pump has efficiency = Qh / W = Qh/(Qh-Qc) = Th/(Th-Tc) this can be greater than one so False 4) True