Torricelli's Law states that the speed of a fluid flowing out of an opening under the force of gravity is proportional to the square root of the product of twice the acceleration of the gravity multiplied by the height h, the distance between the level of the surface and the center of the opening:

$v\; propto\; sqrt\{2gh\}$

The law was named after the Italian scientist Evangelista Torricelli who discovered this law (not in this form) in 1643.This law is mainly used in areas of chemical engineering and mechanical engineering.

References

• Stanley Middleman, An Introduction to Fluid Dynamics: Principles of Analysis and Design (John Wiley & Sons, 1997) ISBN 978-0-471-18209-2