Continuity Theory
Reference from the original Physics I textbook.
- Continuity Theory
The same amount of fluid coming in through one area must be the same amount coming out from another area.
For steady incompressible flow, A₁v₁ = A₂v₂, where the v values are mean speeds normal to the sections.
A₁, A₂ = cross-sectional areas (m²); v₁, v₂ = mean flow speeds normal to those sections (m/s).

- Related Glossary Terms
- Index
Chapter 8 - Bernoulli’s Equation
Chapter 8 - Bernoulli’s Equation
Chapter 8 - Bernoulli’s Equation
Reviewed physics notes (2)
These corrections keep the original lesson’s purpose while fixing errors in the source edition.
- Continuity conserves scalar volume flow, not vector velocity. — Reference 1
- Definitions must agree with scalar continuity law. — Reference 1
Glossary and deeper reading · 1 refreshers
These editorial refreshers supplement the reading. Definitions and examples are added guidance; original source wording and recorded answers remain in their original context.
-
Bernoulli’s equation
Bernoulli’s equation relates pressure, fluid speed, and elevation along a streamline in steady ideal flow. Its usual form assumes an incompressible, nonviscous fluid and no added or removed mechanical energy along the path. For example, in a horizontal pipe narrowing under those assumptions, higher flow speed accompanies lower pressure.