1. ## Re: Impact formula

At 100 yards a bullet will rise somewhat due to correcting the sight. If sighted for 100 yards, the bullet will rise above the line of sight. By correcting for gravity, the bullet will not fall in a short range. The monkey will.
Personally I doubt I'd choose to shoot the monkey anyway.
I don't think I used the term "lead". I suggested anticipating where the monkey will be, aim there.

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## Re: Impact formula

A bullet won't start it's decent untill it has finished it ascent, which is distance which takes time. In a short period of time it can travel and fair distance. Basically a fired bullet won't start its decent untill it has hit the monkey which is falling or traveled quite some distance.

3. ## Re: Impact formula

Lets get back to breaking blocks and boards and black belts and stuff.
I'm an ol man but maybe the docs in the ER can give some insight when they roll the stretcher in with part of the door still attached to yer head.I did enjoy the swinging a one lb hammer story. I figure these are in the 14 lb range.

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## Re: Impact formula

Originally Posted by idacal
and to mess it up more why can a 16 lb sledge move a pin that a 20 ton press will not budge
The foot lbs of energy in an impact are multiplied by the deceleration distance.

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## Re: Impact formula

Willie, you gave a distance to monkey of 100 yards (300 feet) and speed of bullet from your first post of 2000fps. At that speed it takes 150 milli seconds for bullet to hit monkey. If the monkey lets go at the exact time bullet is fired then the monkey will fall only 8.6 inches. You didn't say how big the monkey is but 8.6inches below his heart should give you a heart shot.

You didn't use the term lead or Kentucky windage but adjusting or "anticipating" is leading or Kentucky windage imo.

Sandy, this old physics exercise was assuming a perfect world, level barrel, no air resistance or wind. Gravity, force and motion were the intended point to help Willie understand impact formula. He said its way over his head tho so there's no use trying any further, besides, he's adding trees and monkeys into the equation that makes it even more difficult to help him.

How I was explained: at the same time one bullet is fired from a level barrel, a second is dropped from the same elevation. Both fall at the same speed and would hit the ground at same time. The fired bullet does not rise above the horizon but the horizon does fall due to curvature of the Earth. If the Earth was flat, they would hit the ground at the same time but because horizon drops, the fired bullet has more distance to hit ground than the bullet with no horizontal vector. Quote from a physics book, " many people including hunters seem to have initial difficulty in believing." The picture shows a bullet fired and casing ejected land on the ground at the same time. It's a study in gravity, a weak but constant force.

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## Re: Impact formula

Free fall is key here. There's a huge difference between a free fall and being propelled in some direction. Free Fall, free fall. Fire two shots at the same time, one straight up,,,,,,, one straight down. will both projectiles hit the ground at the same time ??

Of course, if the bullet hits the monkey then I guess they both do hit the ground at the same time in a vague sort of way.
Last edited by Sandy; 06-08-2019 at 11:36 AM.

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## Re: Impact formula

The physic book did say that many people don't get it but, a bullet fired with barrel level will hit at the same time that a bullet dropped from same elevation at same time. Being propelled in another direction does not escape gravity unless traveling at 25,030 miles per hour. That is the escape velocity for Earths gravity.

Again, from physics book: "this result leads to a most interesting situation, which many people, including hunters, seem to have difficulty in believing."

"After hunters think about this situation, they soon remember that to counteract the gravitational pull on the bullet, the rear sight on a rifle is adjusted so that the rifle is actually aimed a small distance above the target."

Some newer ACOG type rifle scopes use stadia or graduation marks to determine range to correct offset or Kentucky windage.
Last edited by Insaneride; 06-08-2019 at 12:16 PM. Reason: Spelling

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## Re: Impact formula

That's where the physicist is actually off. Hunters do get it, he doesn't. Hunters know full well how guns are "sighted in" and have no use for one that isn't sighted in. A firearm not sighted in is nothing more than a bang stick. No hunter will ever just fire a firearm with the barrel parallel to the ground. If a duck is high in the air, we 'aim' high in the air. We even take into account true ballistic distances (gravity distance) vs ground distance when shooting extreme uphill/down hill situations. Snipers even take the coriolis effect when shooting long distances. I doubt the physicist took that into account. Yes hunters and sportsmen do get it.

The scenario was shoot the monkey, not fire a firearm parallel to the ground. We know how to hit the monkey.
Last edited by Sandy; 06-08-2019 at 12:53 PM.

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## Re: Impact formula

The bullet fired, case ejected, thing is somewhat strange.

The case falls at a speed that will eventually approach terminal velocity. It takes time to reach terminal velocity. A hail stone takes a bit to reach the 90ish mph before it hits yer noggin. Drop the hail stone from 3 feet above your head...……….stand under a storm, and let a hail stone hit yer noggin...…...you'll get my drift

So, we got the case hitting the ground at a given time, I can buy that. But what gives me pause is the relationship between that short fall (albeit at less than terminal velocity), and the variable distance the bullet might travel. Are ya sighting it at something 100yds, or something at 800yds. There's gotta be a difference somewhere. The only variable I can see is the sighting distance...…….the case will drop at a steady rate whatever distance the bullet strikes.
Last edited by farmersammm; 06-08-2019 at 07:12 PM.

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## Re: Impact formula

Far as the sledge hitting the pin. I think it's sort of a matter of square inches. Sledge is packing some force, and it's striking something that's very few square inches. Force is concentrated in those few square inches, as opposed to the sledge striking something equal in area to the face of the sledge, which dissipates the force.

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## Re: Impact formula

Back to the ejected case thing.

I'm sure there's a curve showing the acceleration per distance of fall. It's a constant. Weight doesn't matter. Bowling ball falls as fast as a marble.

But the distance to the target is something wholly unrelated to the constant fall of the cartridge case.

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## Re: Impact formula

Now, if you're talkin' about my earlier comment about the artillery shell falling straight down after it's exhausted its energy from the powder charge.

Yeah, in the perfect cartoon world, it would reach terminal velocity at the same rate as the shell ya just dropped on yer foot. It's reached zero acceleration,, and drops at a theoretical 90 degree angle to the trajectory.

Science is the discipline of observing common phenomena, and trying to put numbers to it. This allows folks to predict outcomes for any given situation, if the mathematical model is correct (something like an axiom that's been proven... yielding a rule)

This involves statistics...………..how many times do ya get the same result within the acceptable realm of the bell curve. There's no way to ACTUALLY 100% PROVE ANYTHING, IT'S ALL A MATTER OF REPEATABILITY GIVING SOME DEGREE OF ACCEPTANCE. Ya don't have to hit yer thumb with a hammer more than a few times to verify that it ain't such a good thing to do That's called "sampling".

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## Re: Impact formula

Anybody stop to ask the monkey how he feels about all this?

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## Re: Impact formula

Originally Posted by farmersammm
Back to the ejected case thing.

I'm sure there's a curve showing the acceleration per distance of fall. It's a constant. Weight doesn't matter. Bowling ball falls as fast as a marble.

But the distance to the target is something wholly unrelated to the constant fall of the cartridge case.
In a vacuum weight doesn't matter. In our atmosphere many things matter, wind resistance being the primary factor most of the time. That's why different objects have differing terminal velocities. What can be said in general terms in the earths atmosphere is that items of similar size and weight (mass and volume) will accelerate and fall at a very similar rate. Visually imperceptible most if the time. A lead dart will obviously out run a sheet of paper in a free fall race. The sheet of paper may take a long time to reach the ground from 10,000 feet, a lead dart not so much.

The problem is when we take a simple classroom science demonstration, designed to convey a concept, and turn it into an absolute with no variances for anything.

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## Re: Impact formula

Yeah, I'm over simplifying. I'm guilty of that.

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## Re: Impact formula

Gordo...…...some ol' fat boy in the Southern Hemisphere, falls offa the tractor.

Bob......some ol' fat boy from Nebraska (Northern Hemisphere), falls offa the tractor.

Given the Coriolis Effect, climate change, and the variable winds...…….

Which one's gonna hit the ground first?

I'm thinkin' the only difference is the language the %^^%\$%#\$@#@#\$% is gonna be.

We could split hairs...…… https://www.introduction-to-physics....r-of-pisa.html I'm an old science guy, so I stick with the Pizza Theory

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## Re: Impact formula

But...…..I'm all in for things Pizza!!!!!!!!!!!!!!!!!!!!!!!!!

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## Re: Impact formula

Originally Posted by Sandy
In a vacuum weight doesn't matter. In our atmosphere many things matter, wind resistance being the primary factor most of the time. That's why different objects have differing terminal velocities. What can be said in general terms in the earths atmosphere is that items of similar size and weight (mass and volume) will accelerate and fall at a very similar rate. Visually imperceptible most if the time. A lead dart will obviously out run a sheet of paper in a free fall race. The sheet of paper may take a long time to reach the ground from 10,000 feet, a lead dart not so much.

The problem is when we take a simple classroom science demonstration, designed to convey a concept, and turn it into an absolute with no variances for anything.
WRONG. Weight or mass does matter in a vacuum, even on earth. Mass of an object or planet in outer space effects the orbits of other planets or mass. The vacuum on Earth or outer space voids air resistance tho but gravity remains even in a vacuum chamber.

Sandy, you were just starting to get close to understanding that a hunter aims above a target to adjust for gravity, then you had to throw duck vectors in. Willis son was wrong and the teacher was rite to aim at the monkeys heart. Willies son wanted aim below if I recall, to lead or anticipate the monkeys vertical gravitational fall but, the bullet will still fall at the same speed of gravity as will the monkey and aiming below will not even hit the monkeys scrotum. He should have said aim abov, I didn't catch that at first and thank you Willie for making me think. This exercise goes back to aiming cannon balls. Why it's so hard to understand in modern days? I don't know.
Last edited by Insaneride; 06-08-2019 at 11:39 PM.

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## Re: Impact formula

Sammy, pointing at flying monkeys above with your 8 pound round or whatever you said will still be drawn to Earth at a rate of 32feet per second squared. No exceptions not even speed. You will get more distance firing above your target but gravity will still be constant.

Even if the monkey in the tree is at say a fifteen degree angle above the shooter, the bullet will still be drawn to Earth at a rate of 32ft/second^2. The bullet at Willies specs of 2000fps and range of monkey of 300 feet takes 0.150 seconds to hit the monkey. In that time, the monkey and bullet falls 8.6 inches. If Willies son aims below the monkey, he's gonna miss. Any questions?
Last edited by Insaneride; 06-08-2019 at 11:40 PM.

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## Re: Impact formula

Originally Posted by Insaneride

Sandy, you were just starting to get close to understanding that a hunter aims above a target to adjust for gravity, then you had to throw duck vectors in.
Just starting eh??

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## Re: Impact formula

Yes

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## Re: Impact formula

And no, a vacuum doesn't meen weightless.

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## Re: Impact formula

Sandy, I still can't grasp the belief that the entire universe is infinite, I just except it and move on. Hope that helps.

And if it is the entire universe then how is it infinite
Last edited by Insaneride; 06-08-2019 at 11:50 PM.

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## Re: Impact formula

Ok Sandy, say a sniper shoots a sitting bad monkey at 500 feet away using a 2000 fps round. It will take 1/4 second to reach the monkey, in that time, the bullet falls two feet, the sniper aims or adjusts for two feet above the monkey. Any questions?

Oh and the monkey is uphill at 20 30 or even fifty degrees above sniper, doesn't matter, bullet is drawn to earth by gravity at a rate of 32/second squared. I hope that helps because my work is done here.
Last edited by Insaneride; 06-08-2019 at 11:58 PM.

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## Re: Impact formula

Actually angle of elevation does matter because now gravity is also helping slow the bullets forward velocity and if the monkey is just sitting there I think it's just asking to get shot.

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