An empirical observation is if one forms drops at a constant flow rate such that the drop time is 1, then the observed drop mass, m(t), varies with 1 according to the equation m(t) = m. + st 3/4 where m. is the "equilibrium" value and s is a 9.44s + 5.37. using these two relationships, it is possible to determine surface tension as a function of surface age by means of the drop weight method. combine these equations to obtain one relating m(t) and 1, where ) is the equilibrium drop mass (and the one to which eq. il-25 applies) and surface age 1. for a particular surfactant solution, the observed drop mass is 80.4 mg for drops formed very slowly and 125.7 mg for drops formed every 2 sec. the radius of the tip used is 5 mm and the density of the solution was 1.03 g/cm'. calculate the equilibrium surface tension and that for a surface age of 2 sec given (a) f = 0.6456; and (b) f = 0.6043. (note refs. 41 and 124.)