Thursday, March 17, 2011

Bouncing Grapes In Soda

Again, as I had mentioned before, I love these kinds of "mundane" experiments and finding the physics behind it.

In the March 2011 issue of Physics Education journal, the section on "What Happens Next?" dealt with a very common phenomenon that a lot of people have seen, most of them while sitting at a bar drinking beers. This time, the scenario uses grapes.

You have a glass of a carbonated drink. You drop an unpeeled grape into it. What happens next? Interestingly enough, similar to dropping raisins and peanuts into such carbonated drinks (or beer), the grape will start to sink, and then after some time, it will float back to the surface. This gets repeated over and over again.

But but happens if you drop a peeled grape? Will it act any differently?

And what is the explanation behind all this?

Just so I won't spoil the fun for those who want to offer their explanations, I won't post what the article in the journal has written (you can, of course, "cheat" and look it up yourself). I will make another follow-up post at a later date and reveal to you the explanation.


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