A tank with a 3m diameter has an 8 cm orifice at the bottom. The tank is currently filled with water to a height of 2.5m above the orifice. If the orifice is opened, how long will it take until the height is 1 m. above the orifice? Assume that the water surface lowers so slowly that Bernoulli's equation gives an accurate value of the water velocity leaving the orifice. (369 s = 6.15 min)