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Old 22nd Dec 2008, 21:42
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Hilife
 
Join Date: Mar 2005
Location: Land of the Angles
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Oxford English Dictionary

Suck


• verb 1 draw into the mouth by contracting the lip muscles to make a partial vacuum. 2 hold (something) in the mouth and draw at it by contracting the lip and cheek muscles. 3 draw in a specified direction by creating a vacuum. 4 (suck in/into) involve (someone) in something without their choosing. 5 (suck up to) informal attempt to gain advantage by behaving obsequiously towards. 6 N. Amer. informal be very bad or disagreeable.

The above Oxford English Dictionary does not suggest that Sucking is to push in a specific direction, but to draw. If I refer to a thesaurus I could look under synonyms for DRAW and come across Pull and Suck.

Force. Means anything that pushes and pulls.

Isaac Newton did not note that the apple was pushed to the ground, but pulled. Your argument is that there are only pushing forces and not pulling (Sucking/Drawing) forces.

The only reason that ambient air pressure pushes air up a vacuum hose is that the vacuum (produced within the cleaner) allows ambient air to overcome that caused by the reduction in air pressure within the vacuum cleaner.

With or without a camber on the upper surface of a wing, the pushing force on the underside of a wing is not increased as a result of the lowering of static pressure on the upper surface, but the static force acting downwards on the upper surface of the wing is reduced as a result of reducing static pressure, thereby allowing the wing to be drawn (sucked/pulled/whatever) into the reduced pressure zone.
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