choose the best answer:
A- An ideal gas enters an adiabatic nozzle at 10 m/s and exits at 300m/s. If the incoming specific enthalpy of the gas is 2,111 kJ/kg,what is the exiting specific enthalpy of the gas inkJ/kg?
Choices: 1: 2021.1 Kj/Kg , 2: 2200.9 kj/Kg , 3: 92011 Kj/Kg ,-2021.2 kj/Kg.
B- A material with a specific heat, Cp, of 5 kJ/kg-K passesthrough an insulated turbine at 4 kg/s. The incoming temperature ofthe material is 100°C and the exiting temperature is 50°C.Determine the shaft work in kW.
Choices: 1: 1000 KW , 2: -1000 KW , 3: 250 KW , 4: -250KW.
C- Which of the following statements about a well-insulatedheat exchanger is false (ignoring kinetic and potential energychanges):
Choices: 1: heat is exchanged between the system and thesurroundings , 2: the 2 materials do not physically mix , 3: energyis exchanged between the materials , 4: the sum of the enthalpychanges equals zero.
D- An open vat contains 1 kg of boiling ammonia at 1 bar.Calculate the time (in seconds) it takes for the vat to empty ifthe heat is added at a rate of 100 kW?
Answer: ?
