MadSci Network: Physics |
My daughter can snap her middle finger forward into water in a way that makes a funny gurgling sound, but no splash. If she doesn't hold her hand just right, the water splashes in all directions. It amazes me that a snap with enough energy to send water flying like that can be absorbed with no splash. I first saw her do this in a swimming pool. Her arm was horizontal, just above the surface of the water. Her wrist was bending slightly downward. She held her middle finger against her thumb, ready to snap down into the water. the tip of her middle finger was parallel to the surface of the water and just above it. She could then repeatedly snap her finger down into the water in a way that made a gurgling sound, but no splash! Sometimes a drop or two of water will travel forward a few inches, that's all. There is a skill to this. I tried it about 20 times before I could do the same thing, but not as consistently as her. Is there a name for this hydraulic effect, and does it have applications for high-speed objects entering or moving through water?
Re: Is there a name for this hydraulic effect, and does it have applications?
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