A drop with an initial radius of 100 um falls through a cloud containing 100 droplets per cubic centimeter that it collects in a continuous manner with a collection efficiency of 0.0800. If all cloud droplets have a radius of 10 um, how long will it take for the drop to reach a radius of 1mm?

Question

A drop with an initial radius of 100 um falls through a cloud containing 100 droplets per cubic centimeter that it collects in a continuous manner with a collection efficiency of 0.0800.  If all cloud droplets have a radius of 10 um, how long will it take for the drop to reach a radius of 1mm?

anonymous · Answer

I have to use the equation dr/dt = v w Ec / 4 rowe(l)

anonymous · Answer

the anwer is 76.5...but i have no idea how to get this into time

amistre64 · Answer

dr/dt is about all i can make out of that equation :)  i got no idea what a collection efficiency is; which might help.  Or how to relate it to the radius of a raindrop ....

amistre64 · Answer

any ideas as to whats what in this equation?

dr/dt = v w Ec / 4 rowe(l)