Discharge through an orifice with Cd=0.64, area=0.01 m² and head=3 m is nearly

Orifice discharge formula: Q = Cd × a × √(2gh). Cd = 0.64 (coefficient of discharge, accounting for contraction and friction), a = 0.01 m² (orifice area), h = 3 m (upstream head), g = 9.81 m/s². Q = 0.64 × 0.01 × √(2 × 9.81 × 3) = 0.049 m³/s m³/s. Cd < 1 because actual discharge is less than theoretical due to vena contracta and energy losses.

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