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:
“The totality of our so-called knowledge or beliefs, from the most casual matters of geography and history to the profoundest laws of atomic physics or even of pure mathematics and logic, is a man-made fabric which impinges on experience only along the edges. Or, to change the figure, total science is like a field of force whose boundary conditions are experience.”
—Willard Van Orman Quine (b. 1908)
“Much of the pressure contemporary parents feel with respect to dressing children in designer clothes, teaching young children academics, and giving them instruction in sports derives directly from our need to use our children to impress others with our economic surplus. We find “good” rather than real reasons for letting our children go along with the crowd.”
—David Elkind (20th century)