A horizontal boiler drum of diameter 3 m and length 10 m contains water to a height of 2.5 m. If it is fitted with an orifice of diameter 15 cm at its bottom with coefficient of discharge of 0.62,...

A horizontal boiler drum of diameter 3 m and length 10 m contains water to a height of 2.5 m. If it is fitted with an orifice of diameter 15 cm at its bottom with coefficient of discharge of 0.62, then determine the time taken for emptying the drum.