Torricelli's Law (Speed of Efflux) (v = √(2gh))
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v = √(2gh)
What each symbol means
| Symbol | What it stands for |
|---|---|
| g | Acceleration due to gravity (m/s²) |
| h | Height of liquid surface above the hole (m) |
| v | Speed of efflux from the hole (m/s) |
When to use this
Derived from Bernoulli's equation assuming tank is open to atmosphere (P = Pa at both hole and surface) and tank cross-section A₂ ≫ hole cross-section A₁ (so surface velocity ≈ 0). Speed equals that of a body falling freely through height h. General form: v² = 2gh + 2(P − Pa)/ρ when tank is pressurized.