# Pressure

**What is Pressure?****Pressure formula, Pressure of an ideal gas, Solids and liquid pressure, Pressure units**:**Pressure**is the amount of steady force acting on a surface, per unit area. Solids, liquids and gases apply a force to the surface due to their weight. The force acting on the unit surface perpendicular to the surface is called the pressure (**P**), and the force perpendicular to the surface is called the pressure force (**F**).

**P = F / A**- P: Pressure
- F: Force
- A: Area

**Solids pressure**- Due to the weight of the solid materials they apply the force to the ground. For this reason, the vertical force, which is the pressure applied by the participants to the ground they are on, is their weight. By changing the applied force and surface area, the size of the pressure can be changed. Participants transmit the force applied to them exactly the same without changing their direction and severity. In some cases, it is tried to reduce the pressure effect by increasing the surface area. The unit can be defined as the force applied to the unit point at time.

**Pressure of an ideal gas**- Gas pressure is linked to many elements. The temperature, the volume of the container, the amount of gas and the number of R are important in calculating the pressure of the gases. If we are going to express them formally;
**P.V = n.R.T**Gas pressure increases as the number of molecules and temperature of the gas increases; The volume of the container where the gas is stored decreases. R number is a fixed number. In closed gaseous gases, pressure is measured with the help of manometers.

**Liquid pressure**- The liquid pressure is the pressure applied to every point of the container due to the weight of the liquid. The liquid pressure is the weight of the liquid column at that point.

- That is,
**p = h x d x g** - (Liquid pressure = height x density x gravity acceleration).
- The liquid pressure does not depend on the shape and width of the cabinet.

**Pressure units**

pascal (Pa) | bar (bar) | atmosfer (atm) | tor (Tor) | |
---|---|---|---|---|

1Pa | ≡ 1 N/m² | 10−5 | 9.8692×10−6 | 7.5006×10−3 |

1bar | 100,000 | ≡ 106 dyn/cm² | 0.98692 | 750.06 |

1atm | 101,325 | 1.01325 | ≡ 1 atm | 760 |

1Tor | 133.322 | 1.3332×10−3 | 1.3158×10−3 | ≡ 1 Torr; ≈ 1 mmHg |

- For example: 1 Pa = 1 N / m² = 10-5 bar = 9.8692 × 10-6 atm = 7.5006 × 10-3 tor
- In physics problems, “
*Pascal (unit)*” is usually used as the pressure unit.