Pressure Units and Conversion Factors Pressure is force per unit area. Pressure
ID: 1035629 • Letter: P
Question
Pressure Units and Conversion Factors
Pressure is force per unit area. Pressure may be expressed in many different units.
Units like pounds per square inch give the units used for force and area. Units that include length, like millimeters of mercury refer to the pressure exerted by a column of the liquid of that height. The unit atmosphere refers to the pressure exerted by the gases in our atmosphere on all objects open to it. Since this varies with height above sea level, an average value at sea level is used and expressed in terms of millimeters of mercury. The Pascal is the name for the SI unit of pressure.
The following abbreviations are used:
The following equivalences provide conversion factors between pressure units.
Note: 1 atm = 1.01325 bar
A student reads a barometer in the laboratory and finds the prevailing atmospheric pressure to be 751 mm Hg. Express this pressure in atmospheres, kilopascals, torrs, pounds per square inch, and pascals.
Hint: 1 atm = 101.3 kPa = 760 torr = 760 mm Hg = 14.69 psi = 1.013×105 Pa
751
An automobile tire is inflated to a pressure of 30.9 psi. Express this pressure in atmospheres, kilopascals, inches Hg, millimeters Hg and torr.
Hint: 1 atm = 101.3 kPa = 29.92 in Hg = 760 mm Hg = 14.69 psi = 760 torr
30.9
The prevailing atmospheric pressure on a plateau in Colorado is 0.779 atm. Express this pressure in pounds per square inch, kilopascals, pascals, millimeters Hg, and inches Hg.
Hint: 1 atm = 101.3 kPa = 1.013×105 Pa = 760 mm Hg = 14.69 psi = 29.92 in Hg
0.779
atmospheres = atm millimeters of mercury = mm Hg Pascal = Pa inches of mercury = in Hg pounds per square inch = psiExplanation / Answer
Hint: 1 atm = 101.3 kPa = 760 torr = 760 mm Hg = 14.69 psi = 1.013×105 Pa
751
30.9
0.779
mm Hg atm kPa torr psi Pa751
0.988 100.1 751 14.52 1.001 x 10^5