In physics, the term total pressure may indicate two different quantities, both having the dimensions of a pressure:
- In fluid dynamics, total pressure refers to the sum of static pressure p, dynamic pressure q, and gravitational head, as expressed by Bernoulli's principle:
- where ρ is the density of the fluid, g is the local acceleration due to gravity, and z is the height above a datum.
- If the variation in height above the datum is zero, or so small it can be ignored, the above equation reduces to the following simplified form:
- In a mixture of ideal gases, total pressure refers to the sum of each gas' partial pressure.
Famous quotes containing the words total and/or pressure:
“Unlike Descartes, we own and use our beliefs of the moment, even in the midst of philosophizing, until by what is vaguely called scientific method we change them here and there for the better. Within our own total evolving doctrine, we can judge truth as earnestly and absolutely as can be, subject to correction, but that goes without saying.”
—Willard Van Orman Quine (b. 1908)
“The area [of toilet training] is one where a child really does possess the power to defy. Strong pressure leads to a powerful struggle. The issue then is not toilet training but who holds the reins—mother or child? And the child has most of the ammunition!”
—Dorothy Corkville Briggs (20th century)