1. In the city water tower, water is pumped up to a level 25m above ground in a pressurized tank with air at 125kPa over the water surface. Assuming the water density is 1000kg/m3 and standard gravity, find the pressure required to pump more water in at ground level. (4) 2. The main waterline into a tall building has a pressure of 600kPa at 5m elevation below ground level. How much extra pressure does a pump need to add to ensure a water line pressure of 200kPa at the top floor 150m above ground? 3. Two tanks are connected as shown in Fig. P2.52, both containing water. Tank A is at 200kPa,v=0.5m3/kg,VA=1m3, and tank B contains 3.5kg at 0.5 MPa and 4000C. The valve is now opened, and the two tanks come to a uniform state. Find the final specific volume? (5) 4. Ammonia at 10C and mass 0.1kg is in a piston cylinder with an initial volume of 1m3. The piston initially resting on the stops has a mass such that a pressure of 900kPa will float it. Now the ammonia is slowly heated to 50C. Find the final pressure and volume. (10) 5. A spherical helium balloon 10m in diameter is at ambient T and P,15C and 100kPa. How much helium does it contain? It can lift a total mass that equals the mass of displaced atmospheric air. How much mass of the balloon fabric and cage can then be lifted