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the_original_Retro t1_ja61ihq wrote

Air doesn't really have a true 'speed'. There is a 'transfer-of-air' speed that is dependent on pressure. Generally, the more there is a difference in pressure, the faster nearby air will move.

At the surface of the planet, all the air above you puts a pressure of 14 pounds per square inch on everything. We don't feel that, because we evolved to not feel it. You can't see it because that air presses in on every possible direction.

But air kinda has a speed.

The "speed of air" is probably best described as the "speed of sound". Sound in air, like a balloon's pop or someone's shout, is transmitted at about 770 miles an hour, or about 1100 feet per second. When you smack your hands together, someone that's 1100 feet away will hear it in one second. When a lightning bolt causes a thunder clap, five seconds later (almost a mile of distance), you'll hear it.

That's probably the best way to describe how "fast" air is.

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dwkindig t1_ja60yzz wrote

Assuming best case (cracked from the top), air will rush in at the velocity dictated by gravity and the mass of the air column directly above it. It would be extremely forceful; the vial, bottle, cup, etc. may not survive the experience. You can create a similar effect with nearly full beer bottles and a good whack – look for videos about cavitation or the "water hammer" effect. XKCD also addressed a similar question in an old "What If?" article, which you may find enlightening and amusing.

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NappingYG t1_ja61dug wrote

Speed of individual air molecules about 500 m/s, so just a bit faster that speed of sound in air.

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barmoglot t1_ja61rh2 wrote

The max velocity is a sound velocity at the standart condition ( 1atm, 273 K) by sqrt(2/(gamma -1)) where gamma is àn isobar to isochore heat capacity ratio

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SpartanJack17 t1_ja62plz wrote

Hello u/DumpTrumpGrump, your submission "How fast is air?" has been removed from r/space because:

  • Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.

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