question:(a little bit tricky) A cylindrical open tank needs cleaning. The tank is filled with water to a height meter, so you decide to empty it by letting the water flow steadily from an opening at the side of the tank, located near the bottom. The cross-sectional area of the tank is square meters, while that of the opening is square meters. How much time does it take to empty half the tank? Express your answer numerically in seconds. Take the free-fall acceleration due to gravity to be meters per second per second. anyone can help me solve this quesiton thank you a lot!