The pressure difference between two points along a horizontal tube through which water is flowing is 2.5 cm of mercury. Calculate the speed of water at a point of smaller cross section if the speed at a point of larger cross section is 2.61 ms`""^(-1)`.

Explanation

To solve the problem, we will use Bernoulli's equation and the principle of conservation of mass (continuity equation) for fluid flow.

### Step-by-Step Solution:

1. **Understand the Given Data:**
- Pressure difference (ΔP) = 2.5 cm of mercury
- Speed at larger cross-section (V1) = 2.61 m/s
- Density of mercury (ρ_Hg) = 13.6 × 10³ kg/m³
...