Air Pressure
Air pressure is the push of air on everything around it, and it changes with the weather.
A closed jar has millions of tiny air bits inside, all pushing out on the glass walls. On a cold day, those bits slow down and push less. On a warm day, they move faster and push harder on the walls. Weather works the same way, with warm and cold air pushing on everything around them.
Explaining air pressure by grade level
Air is all around you, and it pushes on things. When the weather changes, air pushes more or less. A barometer is a tool that shows how hard the air pushes. You can build one from a jar and a straw to see this for yourself.
Projects that explore air pressure
Air pushes down on everything around us — and when that push changes, the weather changes too. Stretch a balloon tight over an empty coffee can and glue a straw to it as a pointer. When air pressure rises, it pushes the balloon down and tips the straw up, turning a coffee can into a working barometer.
Air pressure is the push of air on everything around it. In this experiment, pressurized air shoots sand upward like a lava fountain. The moving air pushes sand grains into the sky, and a fan blows them sideways. Coarse grains land near the vent while fine grains travel farther downwind.
Air pressure is the push of air on everything around it, and it changes with the weather. A barometer tracks that push in millibars, giving you a direct reading of how hard the air presses down at any moment.
Air pressure is the push of air on everything around it, and mapping where that push is strong or weak helps predict weather. A barometer captures daily readings of that pressure. Over two to three weeks, you build weather charts of high and low pressure areas to see how shifting conditions shape what happens locally.
Air pressure is the push of air on everything around it, and it weakens at higher altitudes. You inflate 60 balloons to the same diameter and place groups on the ground floor, the 30th floor, and the 60th floor. Every two hours you measure each balloon's diameter and find that the balloons on the 60th floor shrink the fastest.