Water at 20 C in a pool 10 m in diameter and 2 m deep should be drained using a horizontal plastic pipe 3 cm of diameter and 25 m in length.

Water at 20 ° C in a pool 10 m in diameter and 2 m deep should be drained using a horizontal plastic pipe 3 cm of diameter and 25 m in length. Determine the initial flow in the pipe and the time required to completely drain the pool, assuming that the pressure drop at the inlet of the pipe is negligible. Use a value of 0.022 as the coefficient of friction of the pipe. Check if this value is reasonable by using the initial speed in the pipe.