The vertical water tank, shown has uniform cross section, closed at the top and initial level of water in it is 4.5 m from bottom. The empty space of length L contains air at atmospheric pressure (105 Pa), that can be considered as an ideal gas. When the valve at the bottom is opened, the level of water decreases by 0.5 m when the flow of water ceases though valve remains opened. Neglecting any variation in temperature during the process, find initial length of empty space L in cm. g=10m/s2; density of water =1000kg/m3.

Question

The vertical water tank, shown has uniform cross section, closed at the top and initial level of water in it is 4.5 m from bottom. The empty space of length L contains air at atmospheric pressure (105 Pa), that can be considered as an ideal gas. When the valve at the bottom is opened, the level of water decreases by 0.5 m when the flow of water ceases though valve remains opened. Neglecting any variation in temperature during the process, find initial length of empty space L in cm. g=10m/s2; density of water =1000kg/m3.