Pressure

physics · force · everyday science

Feet sink deeper. When you stand on snow, your weight spreads over your feet. But when you wear skis, that same weight spreads over a much bigger area, so the pressure decreases and you don't sink as far.

Air pushes everywhere. Even though you can't feel it, the air around you is pushing on your body with about 15 pounds of force per square inch. We don't notice because the pressure pushes equally from all directions.

Deep ocean crushes hard. The deeper you go underwater, the more water presses down on you from above. Divers have to wear special suits because the pressure at great depths could squeeze their bodies dangerously.

Tires need pressure. Car tires work by holding air at high pressure inside them. The pressurized air pushes outward and helps support the car's weight while cushioning the ride.

Mountains affect air pressure. The higher you climb a mountain, the less air is above you pushing down, so air pressure gets lower. This is why it can feel harder to breathe at high altitudes.