Why do whips crack? Whips have been discussed in a previous question last year.
I wish to ask a further question on the subject. (I can not comment or reply to the previous question since I am a new member here and my score is too low.)
The explanation why a whip cracks, given by the top rated answer to the aforementioned question, is similar to the one given in the Wikipedia article on whipcracking:
The answer says that the momentum (wave) moving down the whip is concentrated to a gradually smaller part of the whip (at the end, the whiptail), thereby making the speed of the moving part higher to conserve momentum. m*v is constant, m (mass of the moving part of the whip) decreases and therefore v increases. This is how the high (supersonic) speed of the whip end is produced, according to this answer.
The explanation given in the answer is, at least to me, similar to comparing the whip to the sliding hammer we use to remove the break pads (or ball bearings) in our cars. You set a weight in motion by pulling on it and and when it comes to a sudden stop at the end something happens. What happens in the sliding hammer is that the other end experiences a yank. But using the hammer, there is no "energy concentration" with e.g. supersonic speed like in the whip, involved. (To me the break pads would just be like the handle of the whip. The sliding weight of the sliding hammer would be like the wave travelling down the whip.)
What I do not understand in this explanation is thus the following:
In a whip, the momentum is moving down the whip, away from the person holding it. To neutralize this momentum (when the wave of the whip reaches the end) you would just need to pull on the whip's handle in the opposite direction. (force f during T (the period for the wavelength) ft=momentum mv). Nothing more would be needed to neutralize the momentum. I can not see how this answer explains the extremely high (supersonic) speed of the whip tail.
 A: The hammer is not a good analogue because it deals with diminishing distance, not diminishing mass ( which would enter $p=mv$).
You are correct that if you moved fast enough backwards from the handle you would neutralize the crack of the whip, except from the handle you can only transfer momentum to the whole mass of the whip, which means, to neutralize the end velocity the whole whip has to move backwards at supersonic speed, making the force your hand has to supply quite large. I believe that it is not doable. Maybe one could make an experimental setup with a machine pulling back the handle of the whip with enough force.
Edit: found a nice study about how the whip end makes the sound:

Previous whip work (one of just three papers on the subject in the past century) had resulted in the puzzling observation that the sonic boom occurs when the tip of the whip is traveling at about twice the speed of sound. But if the tip were truly the cause of the crack, why wasn't the sound heard earlier, when the tip first reached the speed of sound? Goriely and McMillen's calculations have revealed the answer. "The crack of a whip comes from a loop traveling along the whip, gaining speed until it reaches the speed of sound and creates a sonic boom," Goriely says. He notes that even though some parts of the whip travel at greater speeds, "it is the loop itself that generates the sonic boom."

