Superheated steam at 20 mpa, 480°c enters the turbine of a vapor power plant. the pressure at the exit of the turbine is 0.5 bar, and liquid leaves the condenser at 0.4 bar at 75°c. the pressure is increased to 20.1 mpa across the pump. the turbine and pump have isentropic efficiencies of 95 and 85%, respectively. cooling water enters the condenser at 20°c with a mass flow rate of 70.7 kg/s and exits the condenser at 38°c. determine the mass flow rate of the steam.

How much power could a wind turbine produce if it had the following specifications? cp = 0.45 -d=1.2kg/m3 d=50m v 5m/s

Ahelical coil spring has a mean diameter of 50 mm, a wire diameter of 5.5 mm and is wound with a pitch of 10 mm. the spring steel has an ultimate strength of 1250 mpa. find the force needed to compress the spring solid and the wire stress in this condition. state whether the spring will return to its initial length.

To save energy, the air supply to a 2000 ft office has been shut off overnight and the room temperature has dropped to 40°f. in the morning, the thermostat is reset to 70°f and warm air at 120 f begins to flov in at 200ft'/min. the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct. the air pressure is nearly 1 atm everywhere. ignoring heat transfer with the surroundings and kinetic and potential energy effects, estimate how long it takes for the room temperature to reach 70°f. plot the room temperature as a function of time.