How does air pressure work?
Air is pushing on all people and objects with a force of 14.7 pounds per square inch at sea level. (Disclaimer: With the metric system, pressure is measured in Newtons per square meter, which is called a Pascal. With younger kids, it is easy to use pounds per square inch since the units are more familiar and the numbers are more reasonable. To convert pounds per square inch into Pascals, multiply by 6,895.) As you go higher in elevation, there is less air pushing down, so there is less pressure. The change is not that great until you get very high. Heating the air, cooling it, or causing it to move can change the air’s pressure. It is these differences in air pressure that create wind, and make flight possible.
