Bernoulli’s principle

Definition

Bernoulli's principle states that in a steady flow, the sum of the pressure energy, kinetic energy, and potential energy per unit volume is constant along a streamline. It implies that an increase in fluid speed results in a decrease in pressure or potential energy.

5 Must Know Facts For Your Next Test

1. Bernoulli's principle is derived from the conservation of energy for flowing fluids.
2. The principle explains why air pressure decreases when airflow speed increases over an airplane wing.
3. It can be mathematically expressed as: $P + \frac{1}{2} \rho v^2 + \rho gh = constant$, where $P$ is the pressure, $\rho$ is the fluid density, $v$ is the velocity, and $h$ is the height.
4. Bernoulli's equation assumes incompressible and non-viscous fluid flow.
5. Applications of Bernoulli's principle include venturi meters, carburetors, and atomizers.

Review Questions

• What are the key components in Bernoulli's equation?
• How does Bernoulli's principle explain lift on an airplane wing?
• Under what conditions does Bernoulli's equation hold true?

Related terms

Continuity Equation:

A fundamental principle stating that the mass flow rate must remain constant from one cross-section of a pipe to another if there are no sources or sinks.

Pressure:

The force exerted per unit area within fluids; crucial for understanding changes predicted by Bernoulli's principle.

Streamline:

A line representing the path followed by particles of fluid; important for visualizing concepts related to fluid flow such as those described by Bernoulli’s principle.