In article ,
brian whatcott wrote:

Alan Baker wrote:
In article ,
brian whatcott wrote:

Alan Baker wrote:
In article ,
brian whatcott wrote:

Alan Baker wrote:

Interesting comment: what would YOU call it when the fabric on the
upper
wing surface wants to pull away from the ribs?
Air pressure from inside the wing pushing up on it more than the air
above is pushing down...

Let me take a wild guess he you did physics for an uundergraduate
degree. Is that right?

Brian W
No. But it doesn't matter.

If the fabric is moving upward, it can only be because there is more
pressure on its bottom surface than there is on its top surface.

It seems that you are uncomfortable with the entire concept of suction.
For example, how do you suppose suction cups work?

The pressure outside the cup keeps it in place.

Or how about a suction pump that happens to be limited to a 30 ft lift?

Because a vacuum cannot do any actual pulling, you can only lift water
as far as the pressure allows, right.

Well duh, it's also atmospheric pressure that enables suction pumps and
suction cups etc., etc. Yes indeed , but it's an academic issue at
the junior high level, isn't it?

Yup.

OK you certainly cut the cookie at Junior High.
Now can we go back to using terms like suction the way 99.99% of the
technical and scientific population understands it? :-)

Brian W

No one understands "suction" to actually mean a pulling force. Not since
they tried to pump water out of mines and discovered that they could
only "pull" it a certain number of feet, but no further.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg