Question

. A beaker of radius 20 cm is filled with water. Calculate the force of surface
tension on any diametrical line on its surface.
( Surface tension of water is 0.075 N/m

Answer 1

$\sf\huge\bold{Answer:}$

Given :

s = 0.075 N/m  

r = 20 cm

To find :

Force(F) of surface tension on any diametrical line on its surface.

Solution :

s = 0.075 N/m  

ℓ = diameter on the surface of liquid i.e.     

ℓ = 2 × r = 2 × 20 cm = 60 cm

$\fbox{Formula Used :}$

Surface tension = s = (F/ℓ) = [{Force} / {Length}]

Hence F acting on imaginary diameter

F = s × ℓ

∴ F = 0.075 × 60 × $\sf{10}^{-2}$

⇒  F = 4.5 × $\sf{10}^{-2}$ N