The Bernoulli principle states that the pressure inside a liquid increases with depth:

A. True

B. False

C. True only if the channel is horizontal

D. True only if the section of the channel is constant

E. True only if there is no friction

The answer should be B. but why?

Answer: B. False

Explanation:

According to Bernoulli's principle:

"In an ideal fluid (not viscous and without friction) that circulates through a closed conduit, the energy the fluid possesses remains constant along its path."

From there, Bernoulli deduced that the fluid pressure decreases when the flow rate increases. And this has nothing to do with depth.

To understand it better:

In a fluid that circulates through a closed conduit (a pipe for example), it contains energy in two ways:

-Kinetic energy due to its weight and speed.

-Potential energy in the form of pressure.

Now, if the system has constant flow and the total energy (kinetic + potential) is also constant, the energy is transformed every time the transverse area of the tube is modified.

It should be noted that by modifying this transverse area, the flow rate is also modified.

Therefore, as the kinetic energy increases or decreases, this change is compensated by the decrease or increase in pressure (potential energy), since the total energy of the system cannot be created or destroyed.