When a force is applied on a surface, the intensity of the effect is dependent on the magnitude of that force and the area of the surface under application. The larger the area the less the effect or intensity. We resolve to taking a unit area of that surface and measure the force applied over it. This is what is termed to be "Pressure". In simple maths, Pressure = Force / Area.



There is no meaning for "pressure Per Yard", as you have suggested.

Pressure (the symbol: p) is the ratio of force to the area over which that force is distributed.





(Pressure is generated by cross-sectional area (which has a of square unit of say meter,inch,yard.. which resists the flow in hydraulics.As the cross-sectional area decreases pressure at the upstream will be increased and will be decreased at the down-stream)





A yard (abbreviation: yd) is a unit of length. Its a linear measurement.





Pressure = Force / Area





where area will be in





kg/cm^2 or lbs/in^2 or lbs/yard^2 or Newton / mm^2





Pressure = rho*g*h





rho=density in kg/m^3 , g in m / sec^2 & head in m





Pressure = kg/m^3 * m / sec^2 * m = kg.m / sec^2 = N/m^2 =Pascal

Pressure is defined as F/A. That means the units should be weight divided by area, i.e. N/m^2, or pounds per square inch.

The amount of propane in a tank cannot be determined by pressure. At any given temperature, if there is only gas or if the tank is full of liquid, the pressure is the same. Therefore any liquefied gas volume must be determined by its weight.





Since air does not liquefy at the pressures used in tires, pressure and temperature determine volumes of air in tires.

PSI is the standard measurement used to rate tire pressure. We also fill up our propane tanks for BBQ. However sq. in. often doesn't reflect what's understood. Physics equations throw units awkward. How does someone weigh lbs per square? It's better to use pressure Per Yard?