An estimate for the time at which the film rupture takes place can be arrived at as follows-

When the film ruptures, locally, i.e., at some would become zero.

( at where rupture takes place)

(3.16)

Maximum value of (i.e. corresponding to ) would lead us to minimum needed for rupture,

(3.16)

The number of holes formed per unit length can also be estimated.

For each area, there is one hole.

Number of holes per unit area=

(3.17)