Which is a more valuable resource for work production in a closed system –15 ft3 of air at 100 psia and 250°F or 20 ft3 of helium at 60 psia and 200°F? Take T0 = 77°F and P0 = 14.7 psia.

A well-insulated 4-m × 4-m × 5-m room initially at 10°C is heated by the radiator of a steam heating system. The radiator has a volume of 15 L and is filled with superheated vapor at 200 kPa and 200°C. At this moment both the inlet and the exit valves to the radiator are closed. A 120-W fan is used to distribute the air in the room. The pressure of the steam is observed to drop to 100 kPa after 30 min as a result of heat transfer to the room. Assuming constant specific heats for air at room temperature, determine . the entropy generated during this process, in kJ/K. Assume the air pressure in the room remains constant at 100 kPa at all times.

NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Air is compressed by an adiabatic compressor from 95 kPa and 27°C to 600 kPa and 277°C. Assume variable specific heats and neglect the changes in kinetic and potential energies. Determine the isentropic efficiency of the compressor. Use the table containing the ideal-gas properties of air. The isentropic efficiency of the compressor is 0 %.

Required information Problem 07.088 - DEPENDENT MULTI-PART PROBLEM - ASSIGN ALL PARTS NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Air is compressed in a piston-cylinder device from 90 kPa and 20°C to 450 kPa in a reversible isothermal process. Problem 07.088.b - Work done during the process Determine the work done. The work done is kJ/kg.