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Wednesday, October 16, 2013

PHYSICS - FORCES IN LIQUIDS

Forces in Liquids

  • Cohesion is the combined effect of the forces of attraction between particles close to each other in the same substance.
  • Surface Tension is the cohesion at the surface of liquids. Detergents and liquid temperature affect surface tension.
  • Examples of Cohesion and Surface Tension - the rounded shape of a water droplet, clasped pointed hands of divers to reduce surface tension, reduction of surface tension for divers by fountains spraying into the diving pool
  • Adhesion is the combined effect of the forces of attraction between the particles in different substances close to each other.
  • Capillary Action is the effect that causes liquids to rise or fall in fine tubes. The finer the tube, the higher the liquid will rise up the tube.
  • Meniscus - The meniscus is the curved surface of a liquid such as water in a glass or mercury in a thermometer. The curve is caused by the adhesive attraction between the liquid and its container.
  • Examples of Adhesion and Capillary Action - Meniscus of water in a glass, the movement of water through the tubes in a tree