Asubmarine can be treated as an ellipsoid with a diameter of 5 m and a length of 25 m. determine the power required for this submarine to cruise horizontally and steadily at 41 km/h in seawater whose density is 1025 kg/m3. also determine the power required to tow this submarine in air whose density is 1.30 kg/m3. assume the flow is turbulent in both cases. the drag coefficient for an ellipsoid is cd

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.