Question

A liquid of specific gravity 1.5 is observed to rise 3.0 cm in a capillary tube of diameter 0.50 mm and the
liquid wets the surface of the tube. Calculate th excess pressure inside a spherical bubble of 1.0 cm
diameter blown from the same liquid. Angle of contact = 0°.

Answer 1

Answer:

The surface tension of the liquid is

T= 2rhρg = 2(0.025cm)(3.0cm)(1.5gm/cm

3)(980cm/sec 2)

=55dyne/cm

Hence excess pressure inside a spherical bubble

p= R4T

= (0.5cm)4×55dyne/cm

=440dyne/cm 2