Air in a rigid 1-m³ box is at 300 K, 200 kPa. It is heated to 600 K by heat transfer from a reversible heat pump that receives energy from the ambient at 300 K besides the work input. Use constant specific heat at 300 K. Since the COP changes, write dQ = m_air C_v dT and find dW. Integrate dW with the temperature to find the required heat pump work.