adhesion and cohesion


Also found in: Dictionary, Thesaurus, Medical, Legal.

adhesion and cohesion,

attractive forcesforce,
commonly, a "push" or "pull," more properly defined in physics as a quantity that changes the motion, size, or shape of a body. Force is a vector quantity, having both magnitude and direction.
..... Click the link for more information.
 between material bodies. A distinction is usually made between an adhesive force, which acts to hold two separate bodies together (or to stick one body to another) and a cohesive force, which acts to hold together the like or unlike atoms, ions, or molecules of a single body. However, both forces result from the same basic properties of mattermatter,
anything that has mass and occupies space. Matter is sometimes called koinomatter (Gr. koinos=common) to distinguish it from antimatter, or matter composed of antiparticles.
..... Click the link for more information.
. A number of phenomena can be explained in terms of adhesion and cohesion. For example, surface tensionsurface tension,
tendency of liquids to reduce their exposed surface to the smallest possible area. A drop of water, for example, tends to assume the shape of a sphere. The phenomenon is attributed to cohesion, the attractive forces acting between the molecules of the liquid
..... Click the link for more information.
 in liquids results from cohesion, and capillaritycapillarity
or capillary action,
phenomenon in which the surface of a liquid is observed to be elevated or depressed where it comes into contact with a solid. For example, the surface of water in a clean drinking glass is seen to be slightly higher at the edges, where
..... Click the link for more information.
 results from a combination of adhesion and cohesion. The hardness of a diamond is due to the strong cohesive forces between the carbon atoms of which it is made. Frictionfriction,
resistance offered to the movement of one body past another body with which it is in contact. In certain situations friction is desired. Without friction the wheels of a locomotive could not "grip" the rails nor could power be transmitted by belts.
..... Click the link for more information.
 between two solid bodies depends in part upon adhesion.