Chapter 7, Problem 7.34P

2. thermodynamics

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. T₁ = i (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. J = °F Mi Btu/ºR

A rigid, well-insulated tank contains air. A partition in the tank separates 12 ft^3 of air at 14.7 lbf/in2, 40◦F (left side of the tank) from 10 ft^3 of air at 50 lbf/in2, 200◦F(right side of the tank), as illustrated in the figure. The partition is removed and air from the two sides mix until a final equilibrium state is attained. The air can be modeled as an ideal gas, and kinetic and potential energy effects can be neglected. (Note: values for the left side of the tank are denoted with a subscript L, and values for the right side of the tank are denoted with a subscript R). a) Determine the final temperature (in F) b) Determine the final pressure (in lbf/in^2) c) Calculate the amount of entropy produced, in Btu/R d) Is this mixing process reversible or irreversible?

A 30-lb iron casting, initially at 1500°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. T+= 257.4978 (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. 0 = °F i Btu/°R

A 300-lb iron casting, initially at 1500°F, is quenched in a tank filled with 2121 Ib 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. T= i °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

A non-ideal gas contained within a piston-cylinder assembly undergoes two processes, A andB, between the same end states, 1 and 2, where p1 = 10 bar, V1 = 0.1 m3, U1 = 400 kJ and p2 =1 bar, V2 = 1.0 m3, U2 = 200 kJ:• Process A: Process from 1 to 2 during which the pressure-volume relation is pV = constant.• Process B: Constant-volume process from state 1 to a pressure of 2 bar, followed by alinear pressure-volume process to state 2.For each of the processes A and B:a) Sketch the process on a p-V diagram.

A piston-cylinder assembly contains 5 kg of air, initially at 4 bar, 405 °C. The air undergoes a process to a state where the pressure is 1.0 bar, during which the pressure-volume relationship is pV = constant. Assume ideal gas behavior for the air. Determine the work and heat transfer, in kJ. Step 1 Determine the work, in kJ. = -1349.07 W12 Step 2 Determine the heat transfer, in kJ. x kJ Q = x kJ = -1349.07

6. thermodynamics

Air contained in a piston-cylinder assembly undergoes the power cycle shown in the figure below. n = i eTextbook and Media Save for Later 4.5 P (bar) % 1.2 Assuming ideal gas behavior for the air, evaluate the thermal efficiency of the cycle. 3 1.0 v (m³/kg) Isothermal process 3.75 Attempts: 0 of 5 used Submit Answer