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 sceptic] must acknowledge, if he will acknowledge any thing, that all human life must perish, were his principles to prevail. All discourse, all action would immediately cease, and men remain in a total lethargy, till the necessities of nature, unsatisfied, put an end to their miserable existence.”
—David Hume (1711–1776)
“Destiny is an absolutely definite and inexorable ruler. Physical ability and moral determination count for nothing. It is impossible to perform the simplest act when the gods say “no.” I have no idea how they bring pressure to bear on such occasions; I only know that it is irresistible.”
—Aleister Crowley (1875–1947)