Understanding Pressure in Outer Space: Equilibrium and Volume Variations

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The discussion centers on the concept of pressure in outer space, particularly within a hypothetical cube. It explores how pressure acts on small volume elements inside the cube, emphasizing that pressure is equal on opposing sides when in equilibrium. However, it also notes that pressure can vary with volume in different scenarios, leading to different magnitudes of pressure on elements from separate cubes. The conversation touches on the idea of equilibrium in the presence of external forces, such as gravity, which can create pressure gradients. Overall, the thread seeks to clarify the relationship between pressure, volume, and equilibrium in a space environment.
nomorevishnu
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Pressure in outer space!

lets imagine a cube kept in the outer space...and let's take a small element inside the cube...with thickness dy and width dx...or the smalles volume elemnt inside the cube would be another cube right...and...it would be in equilibrium...so the pressure actin on that element from the top and the bottom are going to be the same ...

think abt two cubes ...two different volumes...kept somewhere in the outerspace...take two elements in each of the cubes...the elements r still going to be in equlibrium...but the magnitudes of the pressure actin on both the elemnts r going to different right?...as pressure varies with volume...??
 
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Try to write your post in english.
 
wht do u mean?...r u talkin abt the typos?...guys, is the post not in english?...help with an answer someone please...
 
Those are English words, sure 'nough, but the way that they're put together doesn't make a lot of sense. You've got a lot of partial information and partial questions, none of which add up to a coherent post. Try to rephrase it with all relevant parts included.
 
For starters, cubes of what and where is this pressure coming from?
 
nomorevishnu said:
lets imagine a cube kept in the outer space...and let's take a small element inside the cube...with thickness dy and width dx...or the smalles volume elemnt inside the cube would be another cube right...and...it would be in equilibrium...so the pressure actin on that element from the top and the bottom are going to be the same ...

think abt two cubes ...two different volumes...kept somewhere in the outerspace...take two elements in each of the cubes...the elements r still going to be in equlibrium...but the magnitudes of the pressure actin on both the elemnts r going to different right?...as pressure varies with volume...??
Let me know if I got this right. There's this cube somewhere. Inside the cube, for any volume element dV = dxdydz, the pressure on one side of the element is equal to the pressure on the other side, for all three dimensions. This cube happens to be in equilibrium.

(I imagine it is possible to have a volume with a pressure gradient to be in equilibrium if there's an external force being applied that depends on position. For example, if we ignore the Earth's rotation and the heating of the sun, then the Earth's atmosphere would be in equilibrium, even though it would thin out as the distance R from the Earth's center increases. This is possible because of the Earth's gravity. I imagine the converse would be true too.)

I'm not quite sure what you were asking, but hopefully this helps.
 

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