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Q & A: A straw through a potato?

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Most recent answer: 10/22/2007
Q:
How does this experiement work? Pushing a straw through a potato?
- A.D McD (age 15)
Morrisdale, PA USA
A:
A.D. -

Great question! I actually tried this just a few months ago, and it really does work. The idea is that if you take a potato and just try to push a plastic straw through it, the straw will bend. But if you jab the straw through very quickly, it goes right in. As for why it works, think about this:

If you just have a straw, and you push on both ends exactly straight (not pushing with any tilt at all), you can imagine that you could really push pretty hard without the straw bending. But just as soon as you push a little bit to one side (even for just the tiniest instant), the straw will bend and be crushed. And if you're pushing on it straight, then the longer you push, the more likely you are to accidentally push on it at an angle, bending the straw.

It's the same thing with the potato. If you just try to push the straw in slowly, you spend a lot of time pushing on it, and it doesn't take very long before you push at a little bit of an angle and the straw bends. But if you just jam it straight into the potato very quickly, you don't have to push for very long at all, so the straw doesn't get the chance to bend, and it goes straight in.

-Tamara

(published on 10/22/2007)

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