# How strong is air pressure?

I have read that air pressure is about 100,000 pascalls
which = 100,000 Newtons/m2
which is enough to accelarate a 1kg body with a surface area of 1m2 to 100,000 m/s in one second
which is enough to accelarate a 100kg body with a surface area of 1m2 to 1000m/s in one second.
Is this right. Since i am about 100kg and have a front body surface of about 1m2 is it true that if the air pressure on my back suddenly dissaperaed I would be 1km that way in a little over a second?

## Answers and Replies

Staff Emeritus
Gold Member
An object with a one-meter-squared side experiences a little over a hundred thousand Newtons of force, over that area, due to atmospheric air pressure.

If there were absolutely no opposing forces, such an object with a mass of only 1 kg would experience an acceleration of a little over 100,000 m/s^2.

Of course, it would be quite a feat to arrange a system in which the pressure did not change at all as the object were accelerated. Consider a potato gun or pneumatic rifle. As the projectile begins moving, the cavity behind it gets larger, and the pressure in that cavity is reduced. When fired with atmospheric pressure into a vacuum, the projectile would experience that 100,000 m/s^2 acceleration only instantaneously at the beginning of its movement; at all later times the acceleration would be much less.

Anecdotally, air pressure can store very large amounts of energy. A scuba tank exploding inside a dive shop, for example, can pretty much destroy the whole shop.

- Warren

Mentor
chroot said:
Anecdotally, air pressure can store very large amounts of energy. A scuba tank exploding inside a dive shop, for example, can pretty much destroy the whole shop. [emphasis added]
"Anecdotally"? Did you really think we could let that go without expansion (pun weak, but intended)?