The acceleration of a bubble in water

[Istvan01]

Hi,

I have a question about a rising bubble.
I read that the initial acceleration of a bubble (with negligible mass) in water is 2g, where g is the gravitational acceleration. I understand that if a bubble rise then the water move around it, but I can't derive this equation.
Could someone help me out?

 

[BvU]

I see no reasonable argument for this statement.
What is your reference and what does it say to justify such a claim ?

 

[ZapperZ]

I read that ...

This requires a clear reference to the source.

Zz.

 

[Istvan01]

https://www.ioc.ee/~kalda/ipho/meh_ENG2.pdf
At the 21st page problem 52 is basically the same, after the problem there are hints, but I don't understand them
The solution is 2g

 

[hilbert2]

Looking at the pdf file, the problem 52 seems to assume that the liquid has no viscosity, which isn't true in general.

 

[BvU]

I did find a 2g here but don't see an explanation. And here it gets worse: 3.3 g ! But they do show how the 2g comes about in section 2 (of course ). So your derivation is available.

Must admit I learned to be a bit more open-minded: at first I didn't believe more than g is physically possible...

This one below ? I don't see it. But then again: you say the answer is 2. So: follow the steps and see where you end up
Help us help you and post your working ...

 

[Istvan01]

Thanks, I'm not certain that I can understand your reference because that seems very complicated but I'll try

 

[Lord Jestocost]

Maybe, section 5.10 in https://authors.library.caltech.edu/25017/4/chap5.htm might be of help.