2. Pressure: The pressure per unit area of an object is called pressure.
3. Pressure formula: P=F/S, where the unit of p is Pascal, abbreviated as Pa, 1 Pa = 1 N/m2, and the unit of pressure f is cattle; The unit of stress area s is m2.
4. supercharging method: (1)S remains unchanged, f =；; (2)F is a constant, and S↓ (3) simultaneously puts F = and S↓. The method of decompression is the opposite.
5. The reason of liquid pressure: It is because the liquid is acted by gravity.
6. Characteristics of liquid pressure: (1) Liquid has pressure on the bottom and wall of the container.
(2) There is pressure in all directions in the liquid; (3) The pressure of liquid increases with the increase of depth, and at the same depth, the pressure of liquid in all directions is equal; (4) The pressure of different liquids is also related to the density.
7.* Calculation formula of liquid pressure: (ρ is the density of liquid in kg/m3; g = 9.8n/kg； H is the depth, which refers to the vertical distance from the free surface of the liquid to a point inside the liquid, in meters. )
8. According to the formula of liquid pressure, it can be concluded that the liquid pressure is related to the density and depth of the liquid, but not to the volume and quality of the liquid.
9. The experiment that proves the existence of atmospheric pressure is the Madeborg Hemisphere Experiment.
10. Causes of atmospheric pressure: Air is produced by gravity, and atmospheric pressure decreases with the increase of height.
1 1. The experiment of measuring atmospheric pressure is: Torricelli experiment.
12. The instrument for measuring atmospheric pressure is a barometer. Common barometers are mercury barometer and empty box barometer (metal box barometer).
13. Standard atmospheric pressure: put in an atmospheric pressure equal to 760mmhg. 1 standard atmospheric pressure = 760mmhg =1.013x105pa =10.34m H2O.
14. Relationship between boiling point and air pressure: The boiling point of all liquids decreases when the air pressure decreases and increases when the air pressure increases.
I hope I can help you.