A soap bubble of initial radius is blown at the end of a capillary tube of length and cross sectional radius . It is then left so that the size of the air bubble gradually reduces and the new radius is . If the surface tension of the soap bubble is and the coefficient of viscosity of air is , then the time taken by the bubble to reduce to radius can be represented as
where all quantities are in SI units and is a positive integer. Viscosity of air and surface tension of soap solution is independent of temperature.
Evaluate the value of .