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The USGS Water Science School

Water Science Photo Gallery
Adhesion: Water on Pine Needles

Here is a picture of water drops on pine needles, showing the effects of gravity, adhesion, and cohesion on water. Gravity is shown by the water drops beading up at the bottom of the pine needles trying to fall to the center of the Earth (this applies to every molecule, water or not, in your body, too). The property of adhesion here is counteracting gravity, at least so far. Adhesion causes the water to be sticky to the pine needle, thus preventing it from falling off the needle. Cohesion is seen in the actual water drop—the water molecules stick to each other, forming a drop.

Water drops on pine needles, showing the effects of gravity, adhesion, and cohesion on water.

Credit: J Schmidt; National Park Service.

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Page Last Modified: Thursday, 06-Mar-2014 14:30:48 EST