Fluid mechanics, source-sink question

[liometopum]

In fluid mechanics, the velocity of the liquid going in or out (source-sink) of a hole in a two dimensional model is Q/(2 pi r). http://farside.ph.utexas.edu/teaching/336L/Fluidhtml/node63.html

What is the velocity in three dimensions? Is it Q/(4 pi r^2) ?

 

[Curl]

For a point source, correct.

 

[liometopum]

Thank you, Curl!