Water is being heated in a closed pan on top of a range while being stirred by a paddle wheel. During the process, 30 kJ of heat is transferred to the water, and 5 kJ of heat is lost to the surrounding air. As a result of the heat transfers and stirring the water, the internal energy of the water increases by 25.5 kJ. Determine the shaft work that needs to be supplied to the stirrer if the mechanical efficiency if the stirrer is 0.95