Science
What is Pressure?
Pressure is the amount of force pushing on a given area. The same force concentrated on a small area creates high pressure (like a sharp knife), while spread over a large area it creates low pressure (like snowshoes). It is measured in pascals (Pa).
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains pressure.
Key things to understand
- 1Pressure = force ÷ area. The smaller the area a force acts on, the higher the pressure.
- 2It's measured in pascals (Pa); other units include atmospheres (atm) and bars.
- 3Gases and liquids exert pressure in all directions — air pressure, water pressure, blood pressure.
- 4A sharp blade cuts well because its tiny edge area turns a modest force into very high pressure.
Frequently asked questions
- Why is a sharp knife better than a blunt one?
- A sharp edge has a tiny contact area, so the same force creates much higher pressure — enough to cut. A blunt edge spreads the force over more area, lowering the pressure.
- What is atmospheric pressure?
- The weight of the air above us pressing down. At sea level it's about 101,325 pascals (1 atmosphere), and it decreases as you go higher, where there's less air above.
- How does pressure work in liquids?
- Liquids push in all directions, and pressure increases with depth — which is why your ears feel more pressure the deeper you dive.