Excess pressure on the concave side of the meniscus

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SUMMARY

The discussion centers on the excess pressure observed on the concave side of the meniscus, attributed to the balance of vertical resultant forces due to surface tension. The shape of the meniscus is determined by two primary forces: the adhesion of water molecules to the container's surface and the cohesion among water molecules. In thin tubes, the adhesive force overcomes gravitational force, causing water to rise. Various models exist to explain this phenomenon, but none accurately predict experimental results.

PREREQUISITES
  • Understanding of surface tension and its effects on liquids
  • Basic knowledge of capillary action and its principles
  • Familiarity with molecular adhesion and cohesion concepts
  • Awareness of experimental modeling in fluid dynamics
NEXT STEPS
  • Research the principles of surface tension in liquids
  • Study the effects of capillary action in different tube diameters
  • Explore mathematical models for predicting meniscus shape
  • Investigate experimental methods for measuring surface tension
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Students and professionals in physics, chemistry, and engineering, particularly those interested in fluid dynamics and the behavior of liquids in confined spaces.

Joel Jacon
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Why is there excess pressure always on the concave side or surface of the meniscus?

In my book it is also written that excess pressure balance the vertical resultant forces due to surface tension.
How can a pressure balance a force?

My teacher said that shape of meniscus does not depend on vertical component of force.
Which force is she talking about? Why doesn't the shape of meniscus does not depend on vertical force as there are also curved meniscus so shouldn't vertical force should have some role to play in the curved surface?
 
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There are two forces involved in capillary action which dictate the curvature of the meniscus.
1. The adhesion of the molecules to the surface of the container - so water adheres to glass which drags the sides of the meniscus upwards
2. The cohesion of water which glues the surface of the water together as in raindrops.
So the shape of the meniscus is the balance, basically, of these two forces.

Naturally if a tube is thin the grip on the sides of the tube pulling the water upwards overcomes the force caused by gravity and pulls the water upwards. There are a few models for this but interestingly none of them exactly predict experimental results.

There a few complexities which I have left out for the sake of brevity.
 
Puma said:
There are two forces involved in capillary action which dictate the curvature of the meniscus.
1. The adhesion of the molecules to the surface of the container - so water adheres to glass which drags the sides of the meniscus upwards
2. The cohesion of water which glues the surface of the water together as in raindrops.
So the shape of the meniscus is the balance, basically, of these two forces.

Naturally if a tube is thin the grip on the sides of the tube pulling the water upwards overcomes the force caused by gravity and pulls the water upwards. There are a few models for this but interestingly none of them exactly predict experimental results.

There a few complexities which I have left out for the sake of brevity.

What about the shape of meniscus?
 

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