How is the gas pressure

How is the gas pressure


  • 1 Gas pressure
  • 2 How the emergence of gas pressure
  • 3 gas pressure measuring device
  • 4 factors that depend on gas pressure
  • 5 Gas pressure laws 5.1 The ideal gas pressure 5.2 Law Boyle Charles Law 5.3
  • 5.1 The ideal gas pressure
  • 5.2 Law Boyle
  • Charles Law 5.3
  • 6 References

Gas pressure

Reflects the general pressure on influential force by the substance on the unit area of ​​the other material, the gas pressure is the force exerted by the gas on the walls of the container, and can be observed gas pressure force when the balloon is inflated, when you start inflated will increase area because the pressure of the air molecules inside the balloon is greater than the pressure outside the balloon. [1]

How the emergence of gas pressure

Fluid which gases and liquids pressure in other materials affect the output of objects Kaldguet completely solid, and this seems strange because of the inability of some people to perceive the emergence of pressure from a liquid hammer on iron nail for example, and to be able to imagine the pressure fluid must refer to the pressure formed on the body of a person when they swim a certain depth in the water, the water actually above the person's body will pay down by the power of gravity and affect pressure in it, and when swimming greater depth will increase the value of pressure emerging on the body, such as liquids, the gases affect the pressure in the other also objects, eg this weight of the air in the atmosphere which is air pressure, often we are at the bottom of this atmosphere, characterized by pressure, which affects the human body as a result of the atmosphere as a huge, but we do not feel it because it is the same amount from the beginning, where we do not feel only when you change the amount of value up or down, and can sense this change when the plane take off or when swimming in the deep water, and despite the great pressure value, but it does not affect human because it is issued The power to balance out the value of this pressure. [2]

Atmospheric pressure value change with the rise completely pressure value as a change to the greater depth into the water, the more the height above the ground larger, the less atmospheric pressure value; Therefore, the pressure developing on the high mountain climbers have less; This is because the amount of the air component of the different gases to be less, and vice versa, as the amount of atmospheric pressure affecting the height of 20 thousand feet have half the amount of pressure at sea level. [1]

Gas pressure measuring device

Measured pressure value directly using a device called a barometer invented by the world Torricelli in the period between 1608 m and 1647 m, this device works by using elemental mercury standard as a weight, and consists of a long tube and has a cavity filled with an element of mercury from the only party, and the other party empty mercury is filled with air only, and consists of a cross-section similar atmospheric ground, which leads to a balance between the mercury and the atmosphere, and when changing atmospheric pressure value of the value of changing the high elemental mercury within the tube equivalent to the change in pressure value, and thus measured atmospheric pressure value, the equation physical to measure the value of this pressure is: pressure = mass * acceleration. [1]

Since the value of the acceleration of gravity is equal to 9.80665 m / s ^ 2 almost, pressure expresses influential force in the unit area, the pressure is equal to (body mass * gravity) / space, and to calculate the pressure value inside the barometer device which contains elemental mercury, using the equation the following: p = pgh, where symbols represent the following: [1]

  • P: pressure.
  • p: density.
  • g: fixed terrestrial gravity.
  • h: height of the fluid.

Factors depends on gas pressure

Gas pressure depends on the following factors: [3]

  • Container size: gas pressure depends on the size of the vessel trapped in it, when it becomes less than the container size of the particles of gas less space to move it, and will thus multiplying the walls of the vessel more strongly, leading to increased pressure value emerging.
  • Gas: Increasing the amount of gas in the container will increase the value of the emerging pressure, while reducing the number of particles inside the container will lead to pressure to reduce the value of emerging.
  • Temperature: Reducing the value of the temperature would reduce the value of the gas pressure emerging and vice versa.

Gas pressure laws

As we will mention three laws that link the gas pressure and other factors: [4] comes

Gas pressure ideal

Is characterized by an ideal gas pressure that he has a real size, inelastic collision between molecules due to the forces of attraction between them, and as a result, the real volume of gas is greater than the volume of gas ideal, as the gas pressure real less than the gas pressure of the ideal, and it must be noted that all types of gases take the real ideal behavior of gases at low pressure values, and the temperature is relatively high.

Law Boyle

Scientist Robert Boyle discovered in 1662, the relationship between pressure and volume stability when the value of the temperature, the amount of gas, and formulated the following physical equation: Pα1V → PV = x, where symbols represent the following:

  • P: pressure.
  • V: volume of gas.
  • x: constant scalar depends on the amount of gas, and the temperature given.

In this relationship pressure inversely proportional to the size, and can be formulated as the following equation so when you install fixed numerical values, and define specific conditions: P1V1 = x = P2V2.

Charles Law

Discover the world French physicist Charles in 1787 the relationship between the temperature of the gas and its size, when the value of the pressure is installed, the amount of gas, and formulated as follows: VαT → V = yT, where symbols represent the following:

  • V: volume of gas.
  • T: temperature.
  • y: Tabet scalar depends on the gas pressure and quantity of value, and in this relationship be sized proportional to a positive correlation with temperature, as can be formulated this law in another way when you install the conditions and numerical constants as follows: V1T1 = y = V2T2.


  • ^ A b t w "Gas Pressure",, Retrieved 23-12-2017. Edited.
  • ↑ "What is pressure?",, Retrieved 23-12-2017. Edited.
  • ↑ "Factors Affecting Gas Pressure",, Retrieved 24-12-2017. Edited.
  • ↑ "Gas Laws: Overview",,23-4-2015، Retrieved 24-12-2017. Edited.


We regret it!

Successfully sent, thank you!

Related Posts
• What is the gas pressure
• Gas pressure change
• The concept of gas pressure
• Gas pressure