A liquid of density r and surface tension S rises to a height h in a capillary tube of diameter D. What is the weight of the liquid in the capillary tube? Take angle of contact to be 0º?

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Answer 1 · 2018-07-04T05:45:27

The weight of the liquid is #=piDS " N"#

In a capillary tube, the weight of the liquid is balanced by the force due of surface tension between the liquid and the tube.

The surface tension is #=S#

The diameter of the tube is #=D#

The angle of contact is #theta=0^@#

The circumference of the tube #c=piD#

The force of surface tension is

#F=cScostheta=piDscos0^@=piDS " N"#

And this is equal to the weight of the liquid.