A 15 cm diameter orifice discharging from a tank issues out a jet of diameter 12.75 cm at the vena contracta. The coefficient of contraction is ___________.

What will be the value of Chezy's constant 'C' if the velocity of flow 'V' is 1.506 m/s, bed slope is 1 in 2000 and hydraulic mean depth 'm' is 1.5 m?

Water is flowing through a rectangular channel. The width and depth of the channel are 830 cm and 140 cm, respectively. If the discharge through the channel is 600 cusecs, then the specific energy of flowing water and the value of minimum specific energy are ______ and ______, respectively.