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is head down harder?

Thread Status: Hello , There was no answer in this thread for more than 90 days.
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Seems like Archimedes had it right after all sodeds lol

If air didn't rise, the sea wouldn't be sitting under the atmosphere either :-)))

Just pulling your leg, in reality there are so many other things that complicate matters when it comes to EQ and it's not just as simple as archimedes' principle I think...

look now! im not stupid and i know a thing or two about physics.
the sea isnt sitting under the atmosphere because air goes up! it dose so because the sea is denser (that is by the way how i feel trying to explain this hole thing;)) than the air...so you can say that water goes down.

iv been looking at it the wrong way: i though of the lungs as a bottle of air, which cat be compressed but air dose not move in it anywhere. i should have looked at it as a half full plastic bag - that way air can move in it.

that explains the movement. the only part i didnt figure out yet is:
the air in the lungs dose not know and dose not care (nor the water around the body) that it is in water so "air should go up" when we are out of the water as well...i did my exercise out of the water and it didnt work...:confused:
 
Hi Sodeds - apologies for sure I wasn't saying you are stupid, far from it! :-) I was half-joking about the sea being under the air thing, but if you think about it the reason a drop of water would fall down in air is the same reason a bubble of air will go up when in water. A drop of water in air would still experience upthrust but because of the really low density of air (as you correctly pointed out) this is negligible compared to the weight of the water... If I am wrong about this I apologise.

Anyway I keep confusing myself about a lot of this head down and air going up - happy to discuss more. I think there are a few different things at play. Have sent you a PM too as some of it might get a bit more generic and perhaps a bit off topic :-)
 
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that explains the movement. the only part i didnt figure out yet is:
the air in the lungs dose not know and dose not care (nor the water around the body) that it is in water

I think this is what is confusing you a bit - it does make a difference to the air in the body that the body is immersed in water. Not the same if the body was out of the water...
 
Please forgive an old man for 'talking story'. Following this interesting thread reminded me of a strange experiment that I accidentally did over forty years ago. The helium balloon in my car moved to the right of the roof when the car turned right. I almost drove off the road figuring out why it was apparently defying centrifugal force. Having the same trouble now understanding the roll that gravity plays in this discussion.
 
simos - all in good spirit! im not taking offense and am certain that we are all here to learn so no apologies necessary.:)

i am realy just trying to get the full picture (or why the hell am i not getting what seems to be a simple and intuitive principle).

lets say that the glass bottle is flexible (like our body) and the space around the red balloons is jelly(non-compressible). what diffrence will it make for the red balloons if the container will be submerged in water? do you think that they will rise to the upper part if in water?! i dont think so...am i wrong?

according to Archimedes' principle - what meters is the volume and density of the body. it doesnt matter if it has air in it or two lungs of air or non at all.


imagedemobg.aspx
 
bill - good and old experiment of how we see the subject and ignore the background (we take the air around the balloon for granted). my problem is that i see the air in our air ways as one piece:
if you dive and turn your left chick up and right chick down, will your left chick be more inflated?
 
Hi Sodeds - cool photo :-)

The difference between the photo you posted and the experiment you did in the pool (full exhale when inverted) is that the top of the bottle (ie your mouth) should be open.

So say you inflate those balloons and put the lid on. Then you submerge the whole bottle to 3m. First thing that will happen is that the balloons will shrink in size because of the pressure (do we agree in this?).

Say next you open the top of the bottle - all the air will escape up and the balloons will fill with water right?

Now if you repeat the same but you immerse the bottle upside down and them open the top, not all the air will escape right. In fact if you want to get the air out of the bottle, you need to squeeze the balloons and even then you probably won't be able to get it all out.
 
'...if you dive and turn your left chick up and right chick down, will your left chick be more inflated?'
I think so because the pressure will be greater on your right cheek, even tho the pressure in the air may be the same.
 
'lets say that the glass bottle is flexible (like our body) and the space around the red balloons is jelly(non-compressible). what diffrence will it make for the red balloons if the container will be submerged in water? do you think that they will rise to the upper part if in water?! i dont think so...am i wrong?'
I think that in or out of the water, sealed or not, gravity will pull the jelly down and the balloons will float on it.
 
bill - good and old experiment of how we see the subject and ignore the background (we take the air around the balloon for granted). my problem is that i see the air in our air ways as one piece:
if you dive and turn your left chick up and right chick down, will your left chick be more inflated?

I think too that the left cheek will be more inflated sodeds
 
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