Pressure

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

Pressure is force per unit area applied in a direction perpendicular to the surface of an object.

Definition

Pressure is the amount of force acting per unit area. The symbol of pressure is p or P.

Mathematically:

where:

 is the pressure,

 is the normal force,

 is the area of the surface on contact.

.

Units[edit]

The SI unit for pressure is the pascal (Pa), equal to one newton per square metre (N/m² or kg·m⁻¹·s⁻²)

Pressure units

v t e	Pascal	Bar	Technical atmosphere	Standard atmosphere	Torr	Pounds per square inch
	(Pa)	(bar)	(at)	(atm)	(Torr)	(psi)
1 Pa	≡ 1 N/m2	10−5	1.0197×10−5	9.8692×10−6	7.5006×10−3	1.450377×10−4
1 bar	105	≡ 106 dyn/cm2	1.0197	0.98692	750.06	14.50377
1 at	0.980665×105	0.980665	≡ 1 kp/cm2	0.9678411	735.5592	14.22334
1 atm	1.01325×105	1.01325	1.0332	≡ p0	≡ 760	14.69595
1 Torr	133.3224	1.333224×10−3	1.359551×10−3	1.315789×10−3	≈ 1 mmHg	1.933678×10−2
1 psi	6.8948×103	6.8948×10−2	7.03069×10−2	6.8046×10−2	51.71493	≡ 1 lbF/in2