Date: Mon, 11 Oct 1999 09:22:27 -0600

Author: The Lahrs

Subject: Re: Ball jumping out of water cup

Post:

As the ball and water fall they will be weightless, so surface tension
would do one of two things. If the ball is wetted by the water, then
the meniscus at the water/ball interface will be curved upward and the
ball will be pulled within the water. On the other hand, if the ball
has a wax coating so that the meniscus is curved downward, then the
ball would be ejected from the water. In either case the forces
involved would be very small, so the effect would only be seen easily
during a very long fall or perhaps on a ride in the vomit comet.

John

At 09:48 AM 10/11/99 -0500, you wrote:
>At 09:32 AM 10/11/99 -0500, you wrote:
>>>I don't believe it works that way. Buoyancy is the issue. The ball and
>>>the water are both weightless when it is falling,
>>
>>Therefor, during the freefall time, the ball will move toward the center of
>>the water due to surface tension.
>
>Um... I think I disagree with this. In a weightless environment, the
>pressure in the water should be a constant at all points in the volume. So
>there would be no driving force to push the ball anywhere, right??
>
>-G-
>-----------------------------------------
>Gordon Smith
>National Center for Physical Acoustics
>Coliseum Drive
>University, MS 38655
>slipstk@olemiss.edu
>
>

* John C. and Jan H. Lahr *
* JohnJan@lahr.org *
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