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 the excess pressrue insides a spherical bubble of `1.0 cm` diameter blown from the same liquid . Angle of contact `= 0^(@)`.

Explanation

The surface tension of the liquid is
`T = (rhog)/(2)`
`= ((0.025cm)(3.0 cm)(1.5gm//cm^(3))(980cm//sec(2)))/(2)`
`= 55 "dyne"//"cm"`.
Hence excess pressure inside a spherical bubble
`p = (4T)/(R) = (4 xx 55 "dyne" // "cm")/((0.5 cm)) = 440 "dyne"//"cm"^(2)`.