[Phys-L] Re: fluid

[John Denker <jsd@AV8N.COM>]

Kilmer, Skip wrote:
> Putting your finger at the top of a straw immersed in a glass of water allows you to lift
> the straw. I understand that the difference in pressure between the water near the top of the
> straw and that at its bottom causes the water to rise, but what forces lift the straw? skip

You can't lift the straw with one finger in this situation.

Usually three fingers are used:
   Pinch the sides of the straw between finger #0 (thumb) and finger #2.
   Seal the top of the straw with finger #1.

The static friction against the sides of the straw lifts the straw.
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