Ten cu ft of air at 30 psia and 400°F is cooled to 140°F at constant volume. What is the change in entropy ? Group of answer choices -0. 0581 Btu/oR +0. 20 Btu/oR 0 +0. 581 Btu/oR

R-134a enters a compressor as a saturated vapor at 80 kPa and exits at a pressure of 400 kPa. If 44 kJ/kg of work is required and 5 kJ/kg of heat is lost to the surroundings. What is the outlet temperature. Round your answer to the nearest whole number.

The air in an automobile tire with a volume of 2.60 ft3 is at 70°F and 22 psig. Determine the amount of air that must be added to raise the pressure to the recommended value of 30 psig. Assume the atmospheric pressure to be 14.6 psia and the temperature and the volume to remain constant. The gas constant of air is Ru 53.34 = 0.3704 The amount of air that must be added to raise the pressure is ft·lbf lbm-R 1 psia 144 lbf/ft² lbm. psia-ft³ lbm-R

A vessel contains water. The conditions of the system are: volume of the vessel: V = 0.10 m3 presure of water: P = 200.00 kPa mass of water: m = 5.00 kg specific volume of the saturated water at the pressure: vf = 0.001061 m3/kg specific volume of the saturated vapor at the pressure: vg = 0.885780 m3/kg enthalpy of the saturated water at the pressure: hf = 504.71 kJ/kg enthalpy of the saturated water at the pressure: hg = 2706.30 kJ/k difference of enthalpy of the saturated vapor and saturated liquid at the pressure: hfg = 2201.60 kJ/kg Determine (4)  the quality of twater in the vessel, χ=_____˚

A 0.08-m3 rigid tank contains air at 3 bar and 127°C. The mass of the air in the tank is (a) 0.209 kg (b) 0.659 kg (c) 0.8 kg (d) 0.002 kg (e) 0.066 kg

The pressure gage on a 2.5-m³ oxygen tank reads 500 kPa. Determine the amount of oxygen in the tank if the temperature is 29°C and the atmospheric pressure is 97 kPa. The gas constant of air is R = 0.2598 kPa.m³/kg-K. 0₂ V = 2.5 m³ T°C P₁ = 500 kPa The amount of oxygen in the tank is 2.68 kg.

A rigid tank contains 17 lbm of air at 20 psia and 75°F. More air is added to the tank until the pressure and temperature rise to 30 psia and 85°F, respectively. Determine the amount of air added to the tank.