It is found empirically [Jho, C., and Carreras, M., J. Colloid Interface Sci., 99, 543 (1984)] that in systems which have a time-dependent surface tensions s (t) (such as dilute surfactant solutions), the appropriate drop mass M(t) to be used in the formulae for calculation of s by the drop weight method is given by .

Afan that can provide air speeds up to 60 m/s is to be used in a low-speed wind tunnel with atmospheric air at 35 c. if one wishes to use the wind tunnel to study flat-plate boundary layer behavior up to reynolds numbes of re 10, what is the minimum plate length that should be used? at what distance from the leading edge would transition occur if the critical reynolds nurnber were rer,e = 5 × 105?

Steel balls 12 mm in diameter are annealed by heating to 1150 k and then slowly cooled to 400 k in an air att 325 k and h -20 w/m2 k. assume the properties of the steel to be k- 40 w/m k,p 7800 kg/m3, and cp 600 j/kg k. a. determine whether lumped system method can be used to analyze this problem and if so why" b. determine the time required for the cooling process. c. determine the total amount of heat lost from each ball to the ambient air

An insulated tank truck containing 50,000 pounds of double-distilled, deionized water at 30 °c is pumped into a closed, refrigerated storage tank maintained at 5 °c in a facility located on top of mount mitchell, north carolina (elevation 6,684 feet & average july temperature of 84 °f). a)-determine the volume of the storage tank required to hold the purified water. b)- determine the initial and final pressure differences that must be overcome by a liquid pump assuming the storage tank initially contains air at 5 °c. assume the air is slowly bled out of the storage tank during the water transfer c.) during a routine operation today, the tank is slightly ruptured by a stainless steel pipe and a water acrosol of droplets begins to spray out of the storage tank. state all assumptions and determine the internal pressure within the water droplets produced