pressure + density Flashcards
pressure definition
force per unit area exerted by a fluid on a containing wall
p = F/A
average distance of travel between fluid molecule collisions
mean free path
absolute pressure (increases/decreases) as mean free path increases
decreases
minimum value of absolute pressure
0.0kPa
density definition
mass per unit volume
in gases, a higher density means a lower…
mean free path
compressible definition
density changes significantly with pressure change
incompressible definition
density change is negligible despite pressure change
assume incompressible if (v2-v1)/v2 <=
0.05
most _____ can be considered incompressible
liquids
specific gravity (/density)
equivalent to density but expressed relative to the density of water (for liquids) or air (for gases)
pressure varies with vertical height due to…
gravitational force
simplest pressure measurement device
U-tube manometer
1 bar = _____ kPa
100 kPa
1 atm = _____ kPa
101.325 kPa
1 atm = _____ mmHg
760 mmHg
types of pressure measurement devices
U-tube manometer
well-type manometer
inclined manometer
barometer
bourdon guage
