First we place the ruler on a table so that the middle part of the ruler is on the edge of the desk. If we drop a heavy object on the part that stands out we see that the ruler falls down from the table.
We repeat now the experiment by placing a newspaper sheet extended on the part of the ruler that is on the table. If we draw now the same object on the part that stands out we see that the ruler doesn't fall to the floor.
What makes the ruler stop? Is it an invisible hand or perhaps the weight of the newspaper sheet?
The correct answer is the pressure and the strength in the atmosphere on the newspaper sheet.
It´s very easy and you can do it at home. Will you do it there?
by Marta and Claudia