Suckers, or does a sucker suck? No; maybe they should be called pushers :)
Here is a typical toy bow and arrow |
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It's not just toys that use suction. |
As the suction cup is deformed by pressure air is pushed out. This leaves a vacuum, (or partial vacuum, or lower air pressure under), the suction cup. It is then the pressure of air, (air pressure) pushing the suction cup onto the object.
A little bit more information: When you squeeze the cup against the window, you squeeze out the air from under it. Then the elastic plastic or rubber that the cup is made out of tries to return to its original shape. This causes an area of lower pressure under the cup, and the higher external atmospheric pressure pins it to the window.
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Move and hold your mouse cursor over this image for a very slow motion visual insight into a sucker in action. Click the image to discover more |
Suction cups work because of air pressure. At sea level, atmospheric pressure (force exerted by the atmosphere) constantly pushes down on Earth at about 6.7 kilograms (14.7 pounds) per square inch. Pressing a suction cup against the flat surface forces air out of the space under the suction cup. Because the atmospheric pressure pressing down on the suction cup is greater than the air pressure inside the cup, the surrounding air pressure holds the suction cup in place.
The larger suction cup held more weight. That's because there is more over which atmospheric pressure can push. A larger area means more pressure is holding the large suction cup to the flat surface.
| Watch the power of
suction.. Man climbs building with vacuum gloves BBC TV presenter Jem Stansfield seeming to climb the side of one of the broadcaster's buildings using a very funky homemade contraption based on a vacuum cleaner. The "stunt" was done as a promo for the upcoming BBC show Bang Goes the Theory |
A few sucker and air pressure related links:-
