Chapter 6, Problem 6.50P

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. Tf= 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. O = i Btu/°R

X Your answer is incorrect. A rigid tank whose volume is 4 m³, initially containing air at 1 bar, 295 K, is connected by a valve to a large vessel holding air at 6 bar, 295 K. The valve is opened only as long as required to fill the tank with air to a pressure of 6 bar and a temperature of 350 K. Assuming the ideal gas model for the air, determine the heat transfer between the tank contents and the surroundings, in kJ. Qev = i 88.08 eTextbook and Media Hint Save for Later kJ Attempts: unlimited 4 Submit Answer

Air is compressed in a piston-cylinder assembly from p₁ = 10 lb/in², T₁ = 500°R, V₁ = 9 ft³ to a final volume of V₂ = 1 ft³ in a process described by pv¹.30 = 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 correct. Determine the work, in Btu. W12 = -52.4075 Hint Step 2 * Your answer is incorrect. Determine the heat transfer, in Btu. Q12-13.4475 Btu eTextbook and Media Btu Attempts: 1 of 4 used