A rigid, well-insulated tank of volume 0.9 m3 is initially evacuated. At time t 5 0, air from the surroundings at 1 bar, 278C begins to flow into the tank. An electric resistor transfers energy to the air in the tank at a constant rate for 5 minutes, after which time the pressure in the tank is 1 bar and the temperature is 4578C. Modeling air as an ideal gas, determine the power input to the tank, in kW.