(adsbygoogle = window.adsbygoogle || []).push({}); Rotating water forms a parabola - why??

I've done some experiments involving rotating a beaker of water, and then measuring the height of the parabola that forms. I am now trying to explain this in my write up, but there are some things that I am simply not understanding, and any help would be greatly appreciated.

- Firstly, one diagram I found shows that the centripetal force making the water go in a circle comes from the horizontal component of the buoyancy of the water - but where does this buoyancy come from? I could understand it if there was a ball that needed supporting!

- Is there a name for this behaviour that will yield decent results when googled? I have tired various combinations of parabola, circular motion, centripetal force, rotating water etc etc and have not yet found a decent page explaining this, I have instead found little bits of information across several different sites.

- Is there a 'correct' way of looking at the system? I am explaining it by using centripetal force, and as this increases further away from the centre then the resultant force on the water is more horizontal, so it is consequently steeper (perperndicular to resultant). However I have also seen that it can be explained with centrifugal force pushing the water to the outside, but from what I can tell this is in a rotating reference frame, does it matter?

If anyone can answer any of these questions, or point me to somewhere that can I would be eternally grateful :)

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# Rotating water forms a parabola - why?

**Physics Forums | Science Articles, Homework Help, Discussion**