11) 3 kg or steam initially at 375 kPa and 141.3°C is contained in a piston-cylinder with a diameter of 88 cm. A spring, that is attached to the piston cylinder

and initially at equilibrium at a piston height of 160 cm from the bottom, has a spring constant of 128,450N/m. If the piston raises to double its initial height, find the heat input into the steam.