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Terri Schiavo passes away
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Re: Terri Schiavo passes away (Re: ShiningStar)
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Quote: (Hell no....unless I am getting paid like Tiger Wood... you wont see me doing that) |
I thought the same way you did before I tried it. When you actually play it, it is quite fun.
Here is what Tom wrote as to why there are dimples:
When a golf ball is flying through the air, it has three forces on it. Two of them are gravity and drag from the air. In addition, if the golf ball is spinning, there will be a Magnus force on it (which may point up or down or either side, depending on how it is spinning -- the Magnus force cannot point along the flight path of the ball however.
The main goal of making a golf ball go farther however is to reduce the force of drag as it flies throught the air. In general, turbulence increases drag, because the energy needed to stir the air up and make it swirl around is energy that the ball has lost. One might think that a rough ball will induce more turbulence in the air than a smooth one, but it depends on how fast the ball is going. For balls going slowly through a viscous fluid, then the fluid just moves a bit to the side as the ball passes, and then it returns more or less to where it was. If the fluid motion is smooth, we call the motion "laminar", otherwise it is "turbulent." A ball moving quickly through a fluid like the air will have air flowing in a laminar fashion in some places and in a turbulent fashion in others. Directly behind the ball there will be a turbulent "wake", and surrounding that will be smoothly flowing air. The whole idea behind reducing the drag is to make the turbulent wake small.
The air that slides past the ball very close to it is called the "boundary layer". At the place where the turbulent wake starts is called "separation of the boundary layer" where the smoothly flowing air departs from the ball and does not close up behind the ball nicely but rather swirls around in small vortices. If the boundary layer can be encouraged to stick to the ball a little longer, then the turbulent part of the wake can be reduced. It turns out that adding a little extra turbulence in the boundary layer itself all over the ball allows the main smoothly-flowing air currents to stay closer to the ball and delays the separation of the boundary layer.
Quote: By the way... did you know that a dime has 118 ridges around the edge... (Smiles) |
I am crazy, but I am not that crazy to start counting the ridges around the dime -- ki ki ki ki (my wicked chinese laugh) Did you actually count or heard somewhere?! Just checking.
Quote: You know I am hoping that one day I might be stopped by someone in the street to answer one of these stupid questions and win the infamous million dollar... ha ha ha.. |
Looks like you have a plan for all these. I wish you good luck. The odds of being selected are slimmer than the odds of winning Texas Lottery. :-)
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Terri Schiavo passes away
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