TriAya - 2012-07-19 2:29 AM
cinctly
):
If someone has a good pull, the lift created from that will largely correct the body position.
Furthermore, putting in a really good pull forces you to move and hold your body in the ways you need to have a good body position. It's a natural extension of a solid, well-executed pull.
And once you're pulling well and therefore propelling yourself well in the water, the Bernoulli effect* causes any dragging parts (usually legs, sometimes even lower torso) to lift up and remain on top of the water.
It's not that you "bully" or "force" a pull that's strong enough to overcome drag. It's that doing the pull well a) helps eliminate body positioning that causes drag, and b) moving the body forward well in the water means that the water pressure "lifts" the lower body up and further eliminates drag.
* Get two long strips of paper. Blow down between them. The strips of paper move TOGETHER, not apart. When still, the air pressure on either sides of the paper keeps it in a neutral, non-moving position. When you blow down the middle, you've reduced the pressure in the middle, and thus the air pressure on the outside pushes the paper inward.
If you're moving forward in the water, you've reduced the pressure that your body is causing downward on the water. Thus the greater water pressure from below lifts the body.
N.B. This is not to be confused with arguments about Bernoulli's principle as it applies (or as the case is, doesn't apply) to PROPULSION. Only to body position and sinking/drag. Newton's principles can also be used to explain why, in the case of swimming, good forward movement causes lifting of the body. The takeaway message for any wannabe geeks or good swimmers is that, one way or another for one reason/another/many, if you move forward well, your sinking parts will float and eliminate drag.
it sounds good but...
Again, it has to do with how much energy it takes to correct body position errors. You can do it a bunch of ways and the default for many is to select a high energy way
).