The Secret of Wet Dogs' Shake-Drying Discovered: "Where R is the 'radius of dog' and W, for a rat, is 18 Hz."

http://www.viddler.com/simple/fa8e2a66/

via gizmodo.com

As per the Giz' suggestions, skip the formulas and get right to rats, mice, bears and doggies shakin' they thang!