Surface Tension (Conceptual Question)

AI Thread Summary
Surface tension is defined as the force exerted parallel to the surface of a liquid along a unit length, which supports objects like a needle placed on water. When a needle floats, it appears that the water does not depress, but in reality, the water's surface does slightly bend due to the needle's weight. The concept of surface tension includes this depression, as it is essential for understanding how the needle remains afloat. The angle of contact also plays a role in this phenomenon, influencing how surface tension interacts with the object. Overall, surface tension is a complex interplay of forces that allows objects to float on liquids despite their weight.
SpringPhysics
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Homework Statement


(Sorry if this topic belongs to another forum.)

The definition of surface tension is the force exerted parallel to the surface of a liquid along a line of unit length, perpendicular to the line. So if, hypothetically, when you place a needle on the surface of water, the water does not depress, how is the needle's weight being supported at all? Would the surface tension be completely parallel to the surface of the water, but in no way perpendicular to the line?
 
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SpringPhysics said:

Homework Statement


(Sorry if this topic belongs to another forum.)

The definition of surface tension is the force exerted parallel to the surface of a liquid along a line of unit length, perpendicular to the line. So if, hypothetically, when you place a needle on the surface of water, the water does not depress, how is the needle's weight being supported at all? Would the surface tension be completely parallel to the surface of the water, but in no way perpendicular to the line?

The water does depress.
 
Dadface said:
The water does depress.

So the equation for surface tension takes into account that the water depresses?
 
SpringPhysics said:
So the equation for surface tension takes into account that the water depresses?

Yes,you may get more information if you google angle of contact.
 
Thanks.
 
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