When blowing a hemispherical bubble at the end of a capillary tube of diameter $2.00 ext{ mm}$ dipp

Question

When blowing a hemispherical bubble at the end of a capillary tube of diameter $2.00	ext{ mm}$ dipped in water, what is the excess pressure inside the bubble over the pressure of the surrounding water? (Surface tension of water = $7.3 	imes 10^{-2}	ext{ N/m}$)

Professor PC Thomas Classes · Answer

Excess pressure for a bubble in a liquid (which has only one free surface) is $\Delta P = \frac{2S}{r} = \frac{2 	imes 7.3 	imes 10^{-2}}{1 	imes 10^{-3}} = 146	ext{ Pa}$.