Is there a such thing as suction? *Physics*

[Docalex007]

I just had a long discussion about this with five fellow university students in the cafeteria. We're geeks I know. We went around asking people the first question and it's amazing how many people didn't know the basic principles involved here. Is there a mechanism which sucks? No

Does a vacuum cleaner suck in air? No

When you breathe in air do you suck it in? No

When you sip on a straw do you suck the liquid up into your mouth? No

If you can figure out what's happening instead, consider yourself enlightened.


Consider this just something to think about....for those that thought all these things involved sucking air molecules somehow.

 

[vkartikv]

Capillary forces, surface tension, movement from higher to lower concentrations, any of those a valid answer? I hate physics, I am more of a Chemistry and water guy....

 

[Court_Jester]

If you can figure out what's happening instead, consider yourself enlightened.

Two words: pressure difference.

 

[Docalex007]

Capillary forces, surface tension, movement from higher to lower concentrations, any of those a valid answer? I hate physics, I am more of a Chemistry and water guy....

Not talking about anything involving electromagnetic forces.

Do not confuse electromagnetic attraction with suction. It is impossible to "pull" on molecules by using what the everyday person thinks of as sucking.

 

[Docalex007]

movement from higher to lower concentrations...

That would involve pushing and not pulling. The lower concentration isn't somehow magically attracting the high concentration.

 

[Docalex007]

Two words: pressure difference.

Well sure, nothing fancy that's for sure. But 1) this answer will do little to help someone understand what's happening. And 2) People are so lost to this concept that they would argue for hours about how they can "feel" themselves sucking in air when they breathe in. LOL, I find it amusing. (not really though)

This thread was just to get some people thinking for the new year. :grin:

 

[Kevin T]

I agree completely. You guys are geeks.

 

[Max G.]

Sure. When you "suck in air", what you do is expand your lungs, creating more volume for the air to take up there. This creates a temporarily lower pressure there; air molecules from outside push in more often than inside molecules push out, creating a net influx of air, until the pressure is equalized.

This is the same mechanism that is used in all three of your examples, I think - don't know the specifics of a vacuum cleaner, but based on the name it probably does something of the like.

In all three instances, you do indeed suck in the air - "sucking" is what we call that process that I described in paragraph 1.

 

[DiabloTS]

diffusion....

 

[ceejay]

Suck
1. to draw into the mouth by producing a partial vacuum by action of the lips and tongue: to suck lemonade through a straw.

That sounds like a mechanism to me.

 

[nopiforyou]

Yeah, nothing "sucks" in science. My 8th grade science teacher LOVED to say that. He apparently hated the words suck, and also explained that nothin physically sucks in something.

 

[Supernatural_Serve]

Yeah, nothing "sucks" in science. My 8th grade science teacher LOVED to say that. He apparently hated the words suck, and also explained that nothin physically sucks in something.

Yea, well he never got head, so he's basically clueless about one of the more pleasureable verbs in the language.

 

[nopiforyou]

lol, he got engaged last year. So, maybe he'll get some.

 

[DiabloTS]

Yeah, nothing "sucks" in science. My 8th grade science teacher LOVED to say that. He apparently hated the words suck, and also explained that nothin physically sucks in something.

hahahaa i get it

 

[PimpMyGame]

Yea, well he never got head, so he's basically clueless about one of the more pleasureable verbs in the language.

ha ha ha ha ha ha ha ha ha....

 

[andyroddick's mojo]

suction is just a word for "reduction of pressure"

 

[Docalex007]

LOL @ the head joke.

Yeah you guys are bringing up good valid stuff about what sucking really is. But the fact that a vast portion of the population doesn't understand that sucking is really PUSHING is just ....whatever.

People simply define sucking wrong.