# How To Put A Ruler Under Pressure

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## How To Put A Ruler Under Pressure

Put a Ruler Under Pressure. Mad Scientist Jack Martin will show you how to perform this simple experiment to demonstrate the force of air pressure.

### Step 1: You will need

• a ruler
• a sheet of newspaper

### Step 2: Aim

The aim of this experiment is to demonstrate how air pressure acts on everyday objects.

### Step 3: Method

Balance a ruler on the edge of a table so that half of it is hanging off the table.
Tap the end that is not on the table and see how it falls to the floor
Now place the ruler back on the table again in exactly the same position. This time, cover the end that is resting on the table with a single sheet of newspaper. Tap the other end again and see what happens this time. The ruler will not fall.

### Step 4: Conclusion

Why did this happen? The air in the atmosphere exerts pressure. The greater the surface area of an object the more it can be affected by this air pressure. The first time the ruler was tapped, it easily fell to the floor as the surface area of the ruler is quite small, and so there was little air pressure acting upon it. But when the single sheet of newspaper is placed on top of the ruler, it became far harder to move the ruler, as the air pressure acting upon the newspaper is far greater. Even though the newspaper is not very heavy, the air pressure alone is enough to keep the ruler from being tipped off the table.