Physics · Fluid Mechanics

A cylindrical vessel of height 500 mm has a small orifice at its bottom. Initially, the orifice is closed and the vessel is filled with water up to height H. The top is sealed tightly and the orifice opened. Water flows out until the level stabilizes at 200 mm. Find the decrease in water level (in mm). (Atmospheric pressure = 1.0 × 105 N/m2, density of water = 1000 kg/m3, g = 10 m/s2)