The problem involves calculating the flow $Q$ through a weir using the given equation:

$Q = \frac{2}{3} B \sqrt{2g} H^{\frac{3}{2}}$

Given data:

• $B = 3.0 \, \text{m}$ (breadth of the weir),
• $H = 0.8 \, \text{m}$ (depth of flow),
• $g = 9.81 \, \text{m/s}^2$ (acceleration due to gravity).

Part (i): Evaluate $Q$

We substitute the given values into the equation:

$Q = \frac{2}{3} \cdot 3.0 \cdot \sqrt{2 \cdot 9.81} \cdot (0.8)^{\frac{3}{2}}$

Let’s calculate step by step:

1. $\sqrt{2 \cdot 9.81} = \sqrt{19.62} = 4.429$
2. ( (0.8)^{\frac{3}{2}} = \sqrt{0.8} \cdot