Torricelli's Theorem
is Bernoulli's equation with certain assumption made. This deals with
the set up where you have a large tank with a narrow opening allowing
for the the liquid to flow out. Both the Tank and the the narrow opening
(nozzle) are open to the atmosphere. The fluid velocity of the tank
(water level) is very much slower than the fluid velocity of the nozzle.
The pressure will be the
same because they are open to the atmosphere. The fluid velocity at
region 2 is much slower then the fluid velocity at region 1. Therefore
the fluid velocity at region 2 is negligible. The value of
y_{1}=0.
The equation simplifies to
Example 
A
pump and its horizontal intake pipe are located 12m beneath
the surface of a reservoir. The speed of the water in the
intake pipe causes the pressure there decrease in accord
with Bernoulli's Principle. Assuming nonviscous flow, what
is the maximum speed with which the water can flow through
the intake pipe?



