All Problems

Liquids. Capillary effects

Problem 2.177

Find the lifetime of a soap bubble of radius \(R\) connected with the atmosphere through a capillary of length \(l\) and inside radius \(r\). The surface tension is \(\alpha\), the viscosity coefficient of the gas is \(\eta\).

Reveal Answer
t=2lηR4/αr4t=2 l \eta R^{4} / \alpha r^{4}