Chapter 6, Problem 6.12CU

6.14

answer 96,97,98

One kilogram of water in a piston-cylinder assembly undergoes the two internally reversible processes in series shown in Fig. P6.94.  For each process, determine, in kJ, the heat transfer and the work.

Air contained in a rigid, insulated tank fitted with a paddle wheel, initially at 300 K, 2 bar, and a volume of 2 m³, is stirred until its temperature is 600 K. Assuming the ideal gas model for the air, and ignoring kinetic and potential energy, determine: (a) the final pressure, in bar. (b) the work, in kJ. (c) the amount of entropy produced, in kJ/K. Solve using: (1) data from Table A-22. (2) constant c, read from Table A-20 at 400 K.

Argon gas flows through a well-insulated nozzle at steady state. The temperature and velocity at the inlet are 550°R and 150 ft/s, respectively. At the exit, the temperature is 480°R and the pressure is 40 lb/in?. The area of the exit is 0.0085 ft². Use the ideal gas model with k-1.67, and neglect potential energy effects. Determine the velocity at the exit, in ft/s, and the mass flow rate, in lb/s. Step 1 Your answer is correct Determine the velocity at the exit, in ft/s. V₂- 677.088 Hint Step 2 ft/s Determine the mass flow rate, in lb/s, through the nozzle. m = i lb/s Attempts: 2 of 4 used

Thermodynamics, please help and show all work please.

The system shown is at steady state, steady flow. At inlet 1, the rates of kinetic energy, potential energy and enthalpy entering the system are: KE1 = 0.10 kW, PE1 %3D 0.22 kW, and H1 = 27.0 kW. At inlet 2, the rates are: KE2 = 0.23 kW, PE2 = 0.18 kW, and H2 = 18.0 kVW. At exit 3, the rates are: KE3 = 0.52 kW, PE3 = 0.28 kW, and H3 = 7.0 kW. If the system gives up 5.0 kW of heat to the surroundings, what is the rate of work transfer of the system? Express the answer in kw. %3D KE3 PE3 1 KE. РЕ H. KE2 PE2 На Control volume boundary

6.5

6.72 WP Figure P6.72 shows data for a portion of the ducting in a ventilation system operating at steady state. The ducts are well in- sulated and the pressure is very nearly 1 atm throughout. Assuming the ideal gas model for air with c, = 0.24 Btu/lb · °R, and ignoring kinetic and potential energy effects, determine (a) the temperature of the air at the exit, in °F, (b) the exit diameter, in ft, and (c) the rate of entropy production within the duct, in Btu/min· °R. %3D D = 4 ft V = 400 f/min T = 80°F page2 3 V= 400 ft/min T3 = ? D3 = ? Insulation = 2000 ft/min (AV)2 V2 = 600 f/min T2 = 40°F