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To prove that air has weight and exerts pressure on the earth, this experiment is conducted. A glass tube is filled with mercury. A finger is placed over the end to keep the mercury from slipping out, and the tube is inverted into a cup as shown. The mercury will fall, rise and after a few oscillations, will come to rest at a height above the top of the mercury in a glass equal to about 30 inches.

Pneumatics Experiment

To prove that air has weight and exerts pressure on the earth, this experiment is conducted. A glass…