Chapter 6, Problem 6.84P

A 300-lb iron casting. initially at 600°F, is quenched in a tank filled with 2121 lb of oil, initially at 80°F. The iron casting and oil can be modeled as incompressible with specific heats 0.10 Btu/lb - °R. and 0.45 Btu/lb - °R, respectively. (a) For the iron casting and oil as the system.determine the final equilibrium temperature, in °F. Ignore heat transfer between the system and its surroundings. °F (b) For the iron casting and oil as the system,determine the amount of entropy produced within the tank, in Btu/°R. Ignore heat transfer between the system and its surroundings. Btu/°R

2 kg of air contained in a piston-cylinder assembly undergoes a process from the initial state of T₁ = 400K, v₁ = 0.5 m³ to the final state of T₂ = 600K, v₂ = 0.8 m³. Assume the ideal gas model with cv = 0.72 kJ/kg . K for the air. Kinetic and potential energy effects are negligible. - Can this process occur adiabatically? Demonstrate it with formulas and calculations. If yes, determine the work, in kJ, for an adiabatic process between these states. If not, determine the direction of the heat transfer (in or out of the system). Determine the temperature of the isentropic process with the same initial state, T₁ = 400K, v₁ = 0.5 m³, and the same final specific volume: v₂ = 0.8 m³.

Air within a piston–cylinder assembly, initially at 50 lbf/ in.2, 510°R, and a volume of 6 ft3, is compressed isentropically to a final volume of 0.5 ft3. Assuming the ideal gas model with k = 1.4 for the air, determine the: (a) mass, in lb. (b) final pressure, in lbf/in.2(c) final temperature, in °R.(d) work, in Btu.

During a polytropic process, 10 lb of an ideal gas, whose R = 40 ft.lb/lb.R and cp = 0.25 Btu/lb.R, changes state from 20 psia and 40°F to 120 psia and 340°F. Determine (a)n, (b) U and H, (c) S, (d)Q, (e)∫ , (f)- ∫...... (g)If the process is steady flow during which K = 0, what is Ws?. What is K if Ws = 0? (h)What is the work for a nonflow process?

Argon (molar mass 40 kg/kmol) compresses reversibly in an adiabatic system from 5 bar, 25 0C to a volume of 0.2 m3. If the initial volume occupied was 0.9 m3, calculate the work input in MJ to 3 decimal places. Assume nitrogen to be a perfect gas and take cv = 0.3122 k J / k g K.

Three-tenths kmol of carbon monoxide (CO) in a piston– cylinder assembly undergoes a process from p1 = 150 kPa, T1 = 300 K to p2 = 500 kPa, T2 = 420 K. For the process, W = -300 kJ.Employing the ideal gas model, determine:(a) the heat transfer, in kJ.(b) the change in entropy, in kJ/K.

In a closed and rigid tank, five kg of oxygen (O2), initially at 430°C, exists. Heat transfer from the system to the surroundings occurs at 765 kJ. Assuming the ideal gas model and taking specific heats as constant at 600 K, determine the final temperature, in °C.

Air is compressed in a piston-cylinder assembly from p₁ = 25 lb/in², T₁ = 500°R, V₁ = 9 ft³ to a final volume of V₂ = 1 ft³ in a process described by pv¹.25 = constant. Assume ideal gas behavior and neglect kinetic and potential energy effects. Using constant specific heats evaluated at T₁, determine the work and the heat transfer, in Btu. Step 1 * Your answer is incorrect. Determine the work, in Btu. W12= i -658.845 Btu

3. Air in a piston-cylinder assembly expands isentropically from state 1 where T1 = 40 °C to state 2, where the specific volume is twice that of state 1. Using the ideal gas model with k = 1.1, determine: a. T2 (°C) b. Work per unit mass (kJ/kg)