A horizortal-oriented tube AB of length l :2.5 m rotates with a constant angular velocity ω = 5 rad/s about a stationary vertical axis OO' passing through the end A(figure). Initially the tube is filled with an ideal fluid. The end A of the tube is open, the closed end B has a very small orifice. Find the velocity of the fluid (in m/s) relative to the tube when the liquid column length in tube reduces to h=1 m.