Chapter 6, Problem 6.61P

An ideal gas with R=0.062 BTU/lbm-R and Cv=0.158 BTU/lbm-R undergoes a three-cycle in a closed system. From the initial state of 20 psia and 570 R, the gas is compressed at a constant temperature of 1/5 of its initial volume, process 1-2; it is then heated isochorically to state 3, process 2-3; and finally, expands polytropically with index n=1.5 back to its initial state, process 3-1. Determine the pressures, specific volumes and temperatures at cardinal points around the cycle and the cycle thermal efficiency.

Bernoulli's principle is an example of which law of thermodynamics. Explain why?

Consider a piston-cylinder assembly containing 10.0 kg of water. Initially, the gas has a pressure of 20.0 bar and occupies a volume of 1.0 m3. The system undergoes a reversible process in which it is compressed to 100 bar. The pressure volume relationship during this process is given by: PV1.5 = constant. (a) What is the initial temperature? (b) Calculate the work done during this process. (c) Calculate the heat transferred during this process. (d) What is the final temperature?

Two perfect gas systems undergo reversible expansion under different conditions starting from the same P and V. At the end of the expansions, the two systems have the same volume. The pressure in the system that has undergone adiabatic expansion is lower than in the system that has undergone isothermal expansion. Explain this result without using equations.

For irreversible adiabatic expansion or compression of an ideal gas, work is equal to the internal energy change. Select one: True False

A divider separates 1 lb mass of carbon monoxide (CO) from a thermal reservoir at 150o F. the carbon monoxide, initially at 60o F  and 150 lbf/in2, expands isothermally to a final pressure of 10 lbf/in2 while receiving heat transfer through the divider from the reservoir. The carbon monoxide can be modeled as an ideal gas. (a) For the carbon monoxide as the system, evaluate the work and heat transfer, each in Btu and the amount of entropy produced, in Btu/oR. (b) Evaluate the entropy production, in Btu/oR, for an enlarged system that includesthe carbon monoxide and the divider, assuming the state of the divider remains unchanged. Compare with the entropy production of part (a) and comment on the difference.

0.05 kg of a certain gas in a piston and cylinder is compressed reversibly until the pressure reaches 0.615 MPa. The initial pressure and volume were 0.1025 MPa and 0.03 m3 respectively. Determine the final temperature, the work done on the gas, the heat flow to or from the cylinder walls. i) When the process is according to law PV1.4 = C, ii) When the process is isothermal. (the molecular weight of a certain gas is 44 and y = 1.3).

a=2, f=3 A vertical "2a" cm diameter piston-cylinder device contains an unknown ideal gas at 1 bar and 24 "C. Initially, the inner face of the piston is “4P" cm from the base of the cylinder. The air in system undergoes an internally reversible compression process with a boundary work of “1.f" kJ. The temperature of the gas remains constant during this process. If the molecular weight of the unknown gas is 27 kg/kmol, determine; a) the amount of heat transfer during the process, in kJ, and comment about its direction b) the final pressure of air in the cylinder, in kPa c) the entropy change during the process, in kj/K d) draw P-v and T-s graph in detail. D L

A fluid at pressure of 3 bar, and with specific volume 0.18 m^3/kg, contained in a cyclinder behind a piston that expands reversibly to a pressure of 0.6 bar according to a law: p= C/v², where c is a constant. Show the expansion process on p-V diagram and calculate the net work done by the fluid on the piston.