A. Perform a mass balance for each set of operating conditions with using mass flow rate data to determine the flow rate of rotameter (6 pt in total). b. Compare the calculated mass flow rate value with the measured mass flow rate of rotameter obtained in the experiment. Plot two graphs one for constant cold outlet cases and one for constant hot outlet cases showing the relative error (%) vs Inlet Mass Flow Rate (kg/s). (6 pt, 3 pt each plot)

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 the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct.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.