What is pressure?
Pressure: P = F ÷ A. Pressure is how concentrated a push is: the same force squeezed onto a small area presses much harder than when it is spread over a big one. Air and water press too, harder the deeper you go.
Read how it works: What is pressure? · The history of pressure · More boxes on Glassbox
Chapters in this interactive model
- Pressure: how concentrated a push is: The same force on a small area presses far harder than on a big one.
- Sharp things cut, wide things float: Knives and nails squeeze a force onto a tiny area. Snowshoes, beds of nails and fat tyres spread it out.
- Deeper means harder: pressure in liquids: A rooftop tank, a dam, a diver’s ears and your own blood all follow P = ρ g h.
- We live at the bottom of an ocean of air: Air presses on everything at 101 kPa. It crushes empty spheres, lifts your drink, thins on mountains and cooks your dal.
- Flat tyres, “suction” and the deepest sea: What a gauge really reads, why nothing sucks, 1,086 bar in the Mariana Trench, and a famous paradox.
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