All Problems

Liquids. Capillary effects

Problem 2.177

Find the lifetime of a soap bubble of radius RR connected with the atmosphere through a capillary of length ll and inside radius rr. The surface tension is α\alpha, the viscosity coefficient of the gas is η\eta.

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