What is the excess pressure inside a bubble of soap solution of radius $5.00 ext{ mm}$, given that

Question

What is the excess pressure inside a bubble of soap solution of radius $5.00	ext{ mm}$, given that the surface tension of the soap solution is $2.50 	imes 10^{-2}	ext{ N/m}$?

Professor PC Thomas Classes · Answer

A soap bubble situated in air has two distinct interfaces (inner and outer). Therefore, the excess pressure is $\Delta P = \frac{4S}{r} = \frac{4 	imes 2.50 	imes 10^{-2}}{5.00 	imes 10^{-3}} = \frac{10 	imes 10^{-2}}{5 	imes 10^{-3}} = 20	ext{ Pa}$.