Sweet baby Jesus buy your own gear and measure it yourself. It is not our job to bring you things on silver platters.
When you hang around engineers you will quickly understand that nothing worthwhile comes on platters - so while we try to help, at the end of the day, most of the time, the answer is yours alone to find. Especially if you want to know something very specific that few have cause to care about.
You say you're not the same person who asked the same question in the "Recoil" thread on RFC a couple of weeks ago, but you act just as nagging, whiny, and entitled. And the coincidence of the exact same topics, well, can't be calculated.
David
I find it funny that two people ask the same question, that no engineer wants to touch as a center of mass calculation, and that makes me …”nagging, whiny, and entitled.” As I said earlier, my thick skin doesn’t even register name calling, so call me whatever makes you feel better.
I simply asked the question. The responses have been mostly like yours, dismissive, condensing, accusatory, and have gone off in tangents about energy, velocity, acceleration, and in the end have said we can’t calculate displacement of the rifle. It’s also been quite interesting how many have said this is a measurement nobody is interested in, which is silly.
I began this with the question of how to calculate the displacement, open to anyone and everyone who has a better grasp of the physics, but it soon became obvious there is blind spot with basic physics and which principles apply and which don’t. The principle of a constant center of gravity, call it a conservation of center of gravity if you like, has been rejected across the board for this closed system. It’s a kind of defensiveness I’d think more common with religion or politics.
Nobody who understands, or believes in, simple balancing of masses and displacements, wants to speak up and be poo pooed by other engineers. I don’t blame them - there is no upside for them. There is no upside for me, but I started the thread and find I’m a good judge of common sense, and am still waiting for anyone with an understanding of basic physics to explain why balancing of masses and displacements doesn’t work. When someone says it doesn’t work because of ______ I’m all ears, but simply throwing in thermodynamics isn’t convincing - one of the principles in thermodynamics is mass isn’t created or destroyed in a closed system. Throwing in uneven acceleration isnt convincing because the internal force causing the acceleration has a proportional effect on the two objects moving away from each other.
This has probably reached the best and brightest who wished to contribute, with nearly 200 posts, and unfortunately there is no consensus on how easily the question can be solved. However, just in the elementary searches done since the first post, nothing at all has surfaced discounting my approach, but maybe 50 lectures and basic physics experiments from two dozen universities seem to confirm it.