Please explain the unit of pressure ( atmospheric pressure)?? Thank you so much.
1 Answer
Aug 10, 2017
Pressure, in simple terms, is a measure of the perpendicular force acting on a surface per unit area of the surface, and the simplified equation is
#P = F/A#
The base SI units of force are
#"N"# #= ("kg"*"m")/("s"^2)#
The base SI units of area are
#"m"^2#
So we perform the division of the units:
#P = F/A = (("kg"*"m")/("s"^2))/("m"^2) = color(red)(ulbar(|stackrel(" ")(" ""kg"/("m"*"s"^2)" ")|)#
Or, in regular units,
#color(red)(ulbar(|stackrel(" ")(" ""N/m"^2" ")|)#
This unit is equivalent to the derived unit called the pascal:
#1# #"N/m"^2 = color(blue)(1color(white)(l)"Pa"#
Often, atmospheric pressure is measured in either bars or atmospheres, so it's useful to know the conversion factors:
#1# #"atm"# #= 1.01325# #"bar"# #= 101325# #"Pa"#
and that
#1# #"bar"# #= 10^5# #"Pa"#
