What is the relationship between air pressure and altitude?

With the increase of altitude, the atmospheric pressure decreases. The lower the altitude, the higher the air pressure. In the range of three kilometers, the air pressure decreases by about 133 pa for every increase of 12 m. In addition to altitude, weather, season, temperature, latitude and other factors affect air pressure. The relationship between atmospheric pressure and altitude is negatively correlated.

Weather changes can change the air pressure 10mmHg overnight, which is equivalent to a change between 3500m and 3658m, or a change between 7925m and 8230m.

The history of barometric discovery;

1640 10 Torricelli, the son of Torricelli Galileo, realized that the weight of air in the atmosphere exerted pressure on the mercury in the basin, and this force pressed the mercury into the glass tube. The weight of mercury in the glass tube should be exactly equal to the weight of mercury exerted by the atmosphere on the basin.

When the weight of the atmosphere changes, the pressure it exerts on the basin will increase or decrease, thus causing the mercury column in the glass tube to rise or fall. Weather changes will inevitably cause changes in the weight of the atmosphere. Torricelli discovered atmospheric pressure and found a way to measure and study it.

Torricelli's discovery was the beginning of a formal study of weather and atmosphere, which made us understand the atmosphere and laid the foundation for Newton and other scientists to study gravity. At the same time, this new discovery made Torricelli create the concept of vacuum and invented the basic instrument of meteorological research-barometer.

Application of atmospheric pressure in real life;

Press the plastic hook with sucker on a very flat wall and you can hang things. Piston and centrifugal pumps can pump water from the lower part to the higher part. Squeeze the air out of the pen tube, and then let go to suck the ink into the pen tube.

Cooking food in a pressure cooker is easy. Make a small hole in the tea cover so that the water can be poured out easily. There are also high-pressure boilers, agricultural sprayers, drinking water through straws, and using syringe needles for liquid medicine, all of which are related to atmospheric pressure.