12- 6 Surface Tension -1

Calculate the force required to take awaya flat circular plate of radius 0.01m from the surface of water. The surface tension of water is 0.075  N / m.

Solution:

Given:

Radius                 =       r        =       0.01 m

Surface Tension  =       T       =       0.075 N / m        

Force                   =       F       =       ?

The force per unit area acting at right angle to imaginary line drawn on a free surface of liquid is called surface tension

Therefore,

                             T = F / L

i.e.

                             F = T X L

                             F = T X ( 2 π r )

                             F = 0.075 X ( 2 X 3.14 X 0.01 )

                             F = 0.004713 N