Liquid water flows isothermally at 20°C through a one-inlet, one-exit duct operating at steady state. The duct's inlet and exit diameters are 0.02 m and 0.1 m, respectively. At the inlet, the velocity is 30 m/s and pressure is 1 bar. At the exit, determine the mass flow rate, in kg/s, and velocity, in m/s.

Refrigerant 134a enters an air conditioner compressor at 4 bar, 20 degrees celsius, and is compressed at steady state to 12 bar, 80 degrees celsius. The volumetric flow rate of the refrigerant entering is 5m3/min. The work input to the compressor is 75 KJ per kg of refrigerant flowing. Neglecting kinetic and potential energy effects, determine the magnitude of the heat transfer rate from the compressor, in KW.

A steam turbine operates with an inlet condition of 30 bar, 400 °C, 160 m/s and an outlet state of a saturated vapour at 0.7 bar with a velocity of 100 m/s. The mass flow rate is 1200 kg/min and the power output is 10800 kW. Present the process on the T-v diagram. Determine the magnitude and direction of the heat-transfer rate in kJ/min if the potential energy change in negligible.