These calculations are very useful. Are you getting them from any particular book or source?
These calculations were made by me, based on various sources on the internet, which cover:
• The approximate velocity of the WCC/MC bullet that struck JFK from a range of 88 yards.
• The approximate weight of the bullet.
• The approximate weight of an adult’s human head.
The best source of basic information, on the movement of JFK’s head and the speed of the limousine is, curiously, Josiah Thompson’s 1966 (?) book “Six Seconds in Dallas”, which covers the study by Physics Graduate student William Hoffman. Thompson’s basic idea in the 1960’s was very sound. Get a Physics Graduate student to study the data from the Zapruder film, to see in the motion of JFK’s head is consistent with a bullet strike from the front. To address two questions:
• Immediate after JFK is struck in the head, does his head and torso move backwards with constant momentum.
• If not, can this discrepancy be accounted for by the acceleration of the limousine, or by some other factor.
A Physics Graduate student is the one you would want for this study. When a scientist wins a Nobel Award in Physics it generally is not based on the data that he or she collected, it is based on the data collected by their Physics Graduate students who are working under them. Physics Graduate students are the best for this sort of work, and not the more senior university professors, because they have a lot more available time to put in the ‘grunt work’ of analyzing data.
William Hoffman’s included data showing, for frames 300 through 330 (as I recall):
• The position of JFK’s head, relative to the limousine.
• The estimated velocity of JFK’s head, relative to the limousine.
• The acceleration of JFK’s head, relative to the limousine.
Because the Zapruder film was shot from the side, all measured motions are in the forward/backward direction. There is no good data on any side-to-side motion.
What Hoffman’s data shows is the head:
• stayed mostly still, from z300 through z312,
• moved forward for just one frame interval at 2 mph from z312 through z313,
• gradually accelerated backward from 0.5 mph to 1.8 mph from z313 through z318.
JFK’s body clearly did not move backwards with constant momentum. Not only did the speed pick up, but the amount of mass which moved greatly increased, from JFK’s head alone moving at first, to both the head and torso moving by z315.
And this constant acceleration could not be accounted for by the acceleration of the limousine. While the limousine did accelerate slightly (likely related to the downward slope of the road) from z305 to z312, the acceleration was about one tenth of the amount required to explain JFK’s head acceleration during z313 through z318.
So, the “JFK’s head was pushed backwards by a bullet from the front” fails the physics test. This constant acceleration can only be accounted for by the Neurological Spasm theory.
What is my expertise on this? Not much, but more than most people. I took physics in my senior year of high school. Where I learned about the conservation of momentum and the conservation of energy. I would be lost except the physics of the JFK head shot involves the most basic concepts on Newtonian Physics.
In any case, Josiah Thompson had a good idea. Get a Physics Graduate student to collect the data so he could publish it. The problem is, that Mr. Thompson refused to accept the data he was presented with. But he still had William Hoffman’s data published because it was a good study that Thompson could not get himself to leave out his book. But he ignored the acceleration problem for many years, then ended up falsely claiming that the Zapruder film is too blurry to make accurate estimates.