Each of the following either (a) violates the first law, (b) violates the second

Question

Each of the following either (a) violates the first law, (b) violates the second law, or (c) is correct. For each indicate which law (if any) is violated. Justify your answers with appropriate calculations

A] During an isothermal process a closed system of a perfect gas does 77,816.9ft-lbf of work. Heat transfer of 100 btuto the system takes place during the process.

B] A gas expands adiabatically through a nozzle. The enthalpy and velocity leaving the nozzle are each greater than those entering the nozzle.

C] Cooling water leaves a steam condenser at 150 F. the steam entering the condenser is at 1 psia and quality of 91.7percent.

please show the steps for each process

Explanation / Answer

a)in first low

delta u = q - w

isotermal--> delta u = 0 ==> q = w --> but it not occur

b) H1 + .5v1^2 = H2 + .5 V2^2 --> if V increase ---> h decrease==> but it not occur

c)it is wrong --> saturated water in 1psi is cooler than 150f and can't heat the water more than its temp

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