five

; Standard atmospheric pressure;

There are many experiments that can explain the existence of atmospheric pressure. In history, a famous experiment was done in Madeborg Square, Germany. Two copper hemispheres are put together, and the air inside is pumped out. Two cavalry units were used to pull the hemispheres in opposite directions, thus confirming the existence of atmospheric pressure, which pressed the two hemispheres together. This is the famous hemispheric experiment of Fort Madre; Italian scientist Torricci used liquid mercury to indirectly measure the atmospheric pressure. This experiment uses the equilibrium method, that is, atmospheric pressure is equal to the pressure generated by mercury column; By calculating the pressure of mercury column, the value of atmospheric pressure can be obtained. The atmospheric pressure he measured is equivalent to the pressure produced by a 76 cm high mercury column. A standard atmospheric pressure = 1.0 1× 10.

five

Dad.