I have been told that the hands releasing when trying to crack the whip is the same as the hands releasing the clubhead through the impact zone. This was a pretty common analogy in the 1960s.

BTW, it is believed in some scientific circles the "cracking" sound of a bull whip is caused by the skinny end of the whip breaking the sound barrier, or 750 mph.
(i.e., sonic boom)

American Scientist Online - Crackin' Good Mathematics

If true, we have a ways to go to make the clubhead exceed the speed of sound. GJS