A cylindrical tank with a cross-sectional area of 441 cm squared is filled to a depth of 441 cm with water. At tequals0, a drain in the bottom of the tank with an area of 21 cm squared is opened, allowing water to flow out of the tank. The depth of water in the tank at time tgreater than or equals0 is d(t)equals(21 minus 1.1 t )squared.
At what time is the tank empty?
