Water is falling on a surface, wetting a circular area that is expanding at a rate of 10mm^2/sec. how fast is the radius of the wetted area expanding when the radius is 116mm?

Mostly likely a macro lens

After spending all that time on the research then by all means modify the hypothesis or aim by reporting such. for example the findings did not bring forth what was expected but brought about different yet interesting findings worth exploring so the hypothesis is changed to reflect this new findings.

i may be way off but.