An elastic string of natural length 0.8 m and stiffness 70 nm-1 has one end attached to the ceiling and a mass of 2 kg attached at the other end. the mass is pulled down so that the string extends by 0.60 m and then released. assuming that energy is conserved find the velocity of the mass when the string returns to its natural length.

Water in a partially filled large tank is to be supplied to the roof top, which is 8 m above the water level in the tank, through a 2.2-cm-internal-diameter pipe by maintaining a constant air pressure of 300 kpa (gage) in the tank. if the head loss in the piping is 2 m of water, determine the discharge rate of the supply of water to the roof top in liters per second.