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← Pressure, Winds, Storms, and Cyclones

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Lesson 4 of 14

Why nobody feels it

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6 min

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Air pushes about 4000 N on a square 20 cm wide. Yet you feel nothing. Why?

Air outside pushes in. Pressure inside your body pushes out. They are equal.
Step 1 of 2
  1. Air outside pushes in. Pressure inside your body pushes out. They are equal.
  2. Push a rubber sucker (a rubber cup) onto a tile. Air is squeezed out from under it. Now the outside air presses harder than the air inside.

The rule

You feel nothing. Your body pushes out as hard as the air pushes in.

Air presses on every side of you. The pressure inside your body is equal to it. Equal pressures on both sides balance, so nothing crushes you.

A sucker sticks because outside air presses harder than inside air. On a rough surface, air leaks in under it. Then the pressures are equal, so the sucker does not stick.

Ask what happens in each case.

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