Chapter 6, Problem 6.18CU

Define the following question

Q19: A stationary mass of gas is compressed without friction from an initial state of 2 m3 and 2*105 N/m2 to a final state of 1 m3 and 2*105 N/m2 , the pressure remaining the same. There is a transfer of 360 kJ of heat from the gas during the a process. How much does the internal energy of the gas change

As shown in the figure below, two reversible cycles arranged in series each produce the same net work, Wcycle. The first cycle receives energy QH by heat transfer from a hot reservoir at TH-1000°R and rejects energy Q by heat transfer to a reservoir at an intermediate temperature, T. The second cycle receives energy Q by heat transfer from the reservoir at temperature T and rejects energy Qc by heat transfer to a reservoir at Te - 500°R. All energy transfers are positive in the directions of the arrows. Determine: Hot reservoir at TH lH R1 Reservoir Q at T 20 R2 lc Cold reservoir at Tc We cycle W Wcycle (a) the intermediate temperature T, in °R, and the thermal efficiency for each of the two power cycles. (b) the thermal efficiency of a single reversible power cycle operating between hot and cold reservoirs at 1000°R and 500°R, respectively. Also, determine the ratio of the network developed by the single cycle to the network developed by each of the two cycles, Wcycle-

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

During cardiac surgery, a heart-lung machine achieves extracorporeal circulation of the patient's blood using a pump operating at steady state. Blood enters the well-insulated pump at a rate of 5 liters/min. The temperature change of the blood is negligible as it flows through the pump. The pump requires 20 W of power input. Modeling the blood as an incompressible substance with negligible kinetic and potential energy effects, determine the pressure change, in kPa, of the blood as it flows through the pump. a. Determine the pressure change in kPa.

During a throttling process, the enthalpy (flow energy + internal energy) of a fluid remains constant. But internal and flow energies may be converted to each other.

The inequality in the Clausius inequality holds for .. O B.irreversible Oc totally cycles O D.internally O E. internally O F. irreversible reversible cycles OA totally reversible reversible reversible processes cycles processes processes

No entropy accompanies work as it crosses the system boundary. But entropy may be generated within the system as work is dissipated into a less useful form of energy.

The state of a system is changed from state “A” to state “B” irreversibly, and then repeated using a reversible process. Which of the following is true? a)The entropy change will be same for both processes. b)The pressure change will be the same for both processes.  c)Both “a” and “b”