n a constant volume ‘Otto cycle’, the pressure at the end of compression is 12 times that at the start, the temperature of air at the beginning of compression is 38°C and maximum temperature attained in the cycle is 1950°C. Determine the heat added to the

2. 2 kg of water in a piston-cylinder assembly undergoes two consecutive reversible processes: a. Process 1-2: Isentropic compression from P1 = 0.1 MPa, T1=100°C to P2=D0.5 MPa b. Process 2-3: Isobaric process to a temperature T3 = 400 C Determine heat transfer (kJ), work (kJ), and change in specific entropy (kJ/kgK) for each process.

Q4. A piston-cylinder device whose piston is resting on top of a set of stops initially contains 0.5 kg of helium gas at 100 kPa and 25°C. The mass of the piston is such that 500 kPa of pressure is required to raise it. How much heat must be transferred to the helium before the piston starts rising? Cp = 3.11 kJ/kg K..**

A rigid cylindrical tank stores 80 kg of a substance at 400 kPa and 480 K while the outside temperature is 290 K. A paddle wheel stirs the system transferring shaft work at a rate of 0.7 kW. At the same time an internal electrical resistance heater transfers electricity at the rate of 1.6 kW. A. Do an energy analysis to determine the rate of heat transfer for the tank. B. Determine the absolute value of the rate at which entropy leaves the internal system (at a uniform temperature of 480 K). Answer in kW/K C. Determine the rate of entropy increase in the system's surroundings. Answer in kW/K