In an underground mine, an airflow of \(30\) m\(^3\) s\(^{-1}\) is delivered through a circular opening having a diameter of \(5\) m and a length of \(500\) m. Assuming that there is no change in the surface characteristics, the diameter of the opening, in \(m\), required to double the quantity of airflow at the same pressure loss is . (Rounded off to two decimal places)