Apply the second law of thermodynamics to cycles and cyclic devices.

Introduce the second law of thermodynamics?

Steam in a piston-cylinder assembly undergoes a polytropic process, with n = 2, from an initial state where V₁ = 4.38600 ft³, p₁ = 400 lbf/in², and u₁ = 1322.4 Btu/lb to a final state where u₂ = 1036.0 Btu/lb and v₂ = 3.393 ft³/lb. The mass of the steam is 2.5 lb. Changes in kinetic and potential energy can be neglected. Determine the change in volume, in ft3, the energy transfer by work, in Btu, and the energy transfer by heat, in Btu.

Steam is accelerated in a nozzle from a velocity of 80 to an unknown outlet velocity. S = The area at the inlet to the nozzle is A₁ 50 cm². The temperature and pressure at the inlet to the nozzle are T₁ = 400°C and p₁ = 50 bar, respectively, and the outlet temperature and pressure are T₂ = 300°C and Qout = 120 kW P2 = 20 bar, respectively. During the steady-state flow, heat is lost from the nozzle walls at a rate of 120 kW. For the nozzle: 1 2 400 300 a) Determine the mass flow rate of the steam entering the nozzle, in units of [] b) Determine the velocity at the outlet of the nozzle, in units of [m/s] c) Determine the area at the outlet of the nozzle, in units of [cm²] State T, °C P, bar 60 20 V, m 3 kg 0.04739 0.1308 m vel₁ 80- S A₁ = 50 cm² T₁ = 400 °C P₁ = 50 bar kJ kg kg 2892.9 3177.2 2807.9 3069.5 U, kJ — 1 h, (2) P2 = 20 bar T2 = 300 °C