The Ruler And Atmospheric Pressure
At the edge of a table is placed a very thin ruler so that one third of its lenght is standing out the table. On the part of the ruler which is standing on the table is placed a very light sheet of paper whit a negligible mass . What happens when we hit the ruler really hard (on the part which is standing out the table)?
Hint - The atmospheric pressure has a value of about 100000 Pa and usually occurs when a vacuum is created.
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1 solution
When the sheet of paper is placed on the ruler, a vacuum is created and the force created by the atmospheric pressure is equal to p*S, where p is the atmospheric pressure and S is the surface of the sheet, but since p is 100000 Pa, that force will be extremely huge and the ruler will break. You can try this experiment at home. You only need a very thin solid ruler and a sheet of paper, but you need to make sure there is no air trapped between the table and the sheet and you need to hit the ruler really hard, really fast.