Air enters a compressor with a stagnation pressure of 100 kPa and a stagnation temperature of 35 °C and is compressed isentropically to a stagnation pressure of 900 kPa. Determine the power input to the compressor for a mass flow rate of 0.04 kg/s. Take c_{p} = 1.005 kJ/kg·K, γ = 1.4. (answer in kW)