A water tank has the shape of an inverted right circular cone with its axis vertical and vertex lower most. Its semi-vertical angle is \( \tan^{-1} \bigg(\large\frac{1}{2} \bigg) \). Water is poured into it at a constant rate of 5 cubic meter per minute. Find the rate at which the level of the water is rising at the instant when the depth of water in the tank is 10 m.