Problem Four (25 Points) A 2-m rigid insulated tank initially containing saturated water vapour at 1 MPa is connected through a valve to a supply line that carries steam at 400 C. Now the valve is opened, and steam is allowed to flow slowly into the tank until the pressure inside the tank rises to 2 MPa. At this instant, the temperature inside the tank is measured and found { 300 C. Given: Saturated steam at 1 MPa: U8 = 2582.8 kJ/kg; V8 = 0.19436 m /kg Superheated steam at 2 MPa and 300 C: U8 = 2773.2 kJ/kg; V8 = 0.12551 m /kg a) [8 points] Determine the mass of the steam that has entered the tank b) [7 points] Starting from the general energy balance equation in an integral form, make the necessary simplifications applicable to this problem. c) [10 points) Determine the pressure of the steam in the supply line