Air Holding Up Water - Physics Demo - Atmospheric Pressure

You might not think about it often, but the air around you is constantly pressing in on you from all directions. The air (aka the atmosphere) presses about almost 15 pounds per square inch, at sea level (about 100,000 newtons per square meter).

#physics #science #demo #demonstration #pressure #atmosphericpressure #atmosphere

[xdragonk]

I remembered doing this experiment myself. If I'm not mistaken, some water had to leak out for the pressure inside the cup to be slightly less than the atmospheric pressure for the atmosphere to be propping the sheet onto the cup.

[Study-gk]

Got it! Will cohesive forces (water and plastic) play a role too?

[Mr_stranger_]

Surfce tension, cohesion, adhesion.. Air pressures.. All work there..🚶‍♂️

[ulasmeker]

In the example of finding the total pressure at point P in water, we can assume that the atmospheric pressure, namely the "gas pressure" can go through a liquid which is a different substance form and affect the point P. But why can't we also claim that this gas pressure can succeed to reach the point by passing the solid part? (The gas itself can't pass ofcourse but the pressure can do so)

[switzenne]

I just wish you have a mic on you so we can hear u better

[Audits]

Please explain how atmosphere is pushing up on it

[Aeoluss]

Why does the weight of the water not outweigh the atmospheric pressure? Does the air rushing to the opposite end of the cup pull the plastic and help hold it?

[michaellavery]

The bit of plastic is holding the water.
Take it away and the water falls out.

[jeremycleary]

It wouldn’t hold the water in if there weren’t a vacuum created by the cup being sealed. Or, lightly squeeze the cup and see what happens…

[Datboykeke]

Question. Is their a certain amount where that would no longer hold due to the atmosphere not being able to hold it. I guess my question is does that have limits?

[enbinzheng-line]

Can a plate formed with a metal mesh do the same, right?

[edgewayof]

Can't do that with Steel or hard plastic. You still need suctioning for that to happen.

[axelzaldy]

Not me thinking the glass will floating..

[SwitchVideos]

Gonna have to say, sure it’s the “atmosphere”, but this isn’t explaining what’s going on. As others have pointed out, multiple variables are playing a factor here. Cool trick, but skip an ingredient or step and it fails. YouTube shorts can leave things out I guess

[User-dx]

Will the weight of the cup changes as you said that the surrounding air pushes the plastic ? Please someone who knows the answer comment.
Thank you

[tengo]

Why can't the atmospheric pressure hold the water up without the plastic sheet!?

[바구스-on]

And also the tight air volume in the cup makes the water very lighter? Because it keeps the volume constant.

[Syndicate]

I thought this was a surface tention situation 🤔

[nicholasmarques]

So you're saying that if you placed that plastic on the ceiling it would stay there due to the pressure of the atmosphere? it's not atmospheric pressure keeping it there, dawg.

[rajvardhan]

Actually it happens due to surface tension but atmospheric pressure is also involved . Both added up are just enough to overcome the effect of the weight of the water. It may be said that there is Vacuum as well but no the air inside has just moved to the top of the cup .