12. [-/8 Points] DETAILS MY NOTES SERPSE10 21.A.P.033. ASK YOUR TEACHER In 1816, Robert Stirling, a Scottish clergyman, patented the Stirling engine, which has found a wide variety of applications ever since, including current use in solar energy collectors to transform sunlight into electricity. Fuel is burned externally to warm one of the engine's two cylinders. A fixed quantity of inert gas moves cyclically between the cylinders, expanding in the hot one and contracting in the cold one. The figure below represents a model for its thermodynamic cycle. Consider n moles of an ideal monatomic gas being taken once through the cycle, consisting of two isothermal processes at temperatures 37, and T and two constant-volume processes. Let us find the efficiency of this engine. (Use any variable or symbol stated above along with the following as necessary: R.) P Isothermal 'PI'I!CEHES B C ST, A I s | o T | v 2V, @ (a) Find the energy transferred by heat into the gas during the isovolumetric process AB. Qg = ' (b) Find the energy transferred by heat into the gas during the isothermal process BC. Qsc=' (c) Find the energy transferred by heat into the gas during the isovolumetric process CD. 2 (d) Find the energy transferred by heat into the gas during the isothermal process DA. Qg = | (e) Identify which of the results from parts (a) through (d) are positive. (Select all that apply.) D D 9 (@ - Evaluate the energy input to the engine by heat. Q, = (f) From the first law of thermodynamics, find the work done by the engine. (g) From the results of parts (e) and (f), evaluate the efficiency of the engine. A Stirling engine is easier to manufacture than an internal combustion engine or a turbine. It can run on burning garbage. It can run on the energy transferred by sunlight and produce no material exhaust. Stirling engines are not currently used in automobiles due to long startup times and poor acceleration response. W= Need Help? Submit Answer 13. [-/7 Points] DETAILS MY NOTES SERPSE10 21.C.OP.043. ASK YOUR TEACHER PRACTICE ANOTHER A 1.35 mol sample of an ideal gas, with y = 1.40, undergoes a Carnot cycle described by the PV diagram below. When the gas is in state A on the diagram, the pressure is 22.5 atm and the temperature is 600 K. When it is in state C, the pressure is 1.00 atm and the temperature is 400 K. (Note that the diagram is not drawn to scale. Due to the nature of this problem, do not use rounded intermediate valuesincluding answers submitted in WebAssignin your calculations.) The work done during the cycle equals the area enclosed by the path on the PV diagram. 1) @ 22.5 atm | atm 1.00 atm Submit