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jonoMT
Optics Master Extraordinaire Joined: November/13/2008 Location: Montana Status: Offline Points: 4853 |
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As has been mentioned, it's going to depend on the BC and the atmospheric conditions. But, generally, it's going to be somewhere in the vicinity of of 375 yards for a really good .308 bullet @ 2850. I entered a sight height of 0.0 and a zero of 1 yard in JBM (the minimum allowed) and 0 yards in Ballistica and came up with the same results: At about 363 yards, my Berger 175 gr. OTMs (G7 BC .259) @ 2690 and a station pressure of 24.00 Hg, temp 59F is going to hit the dirt.
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Reaction time is a factor...
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jonoMT
Optics Master Extraordinaire Joined: November/13/2008 Location: Montana Status: Offline Points: 4853 |
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It's a good question, BTW, because it reinforces the concept that we are never shooting a bullet in a straight line to a target out at distance...something you see anytime you watch a quarterback lob a hail mary pass...although not so much from the Pats yesterday. Spraying water through a nozzle on a garden hose is a good way to demonstrate both gravity's effect on a trajectory and the effects of compensating by aiming higher.
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Reaction time is a factor...
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Dale Clifford
Optics Jedi Knight Joined: July/04/2004 Location: United States Status: Offline Points: 5087 |
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this question is asked in most beginning physics classes, the assumptions made about the bc in "flight" are the same as the bc when its drops, (cancel out) the entire arguement is cateris paribus(all things being equal) because the orginal quesion does not contain information outside the given parameters. One of the reasons the profs ask it -- is to see how much shick gets drug into the problem, not related to the basic question' If outsideinformatin is allowed in, when do you stop? It couldbe argued that neither exist because quantum reality is a plasma, or that the numerical methods in the coupled differential equations and the integration steps used in the computer program aren't accurate enough to reflect the difference.
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I love little league baseball-- it keeps the kids out of the house
Yogi Bera |
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Kickboxer
MODERATOR Moderator Joined: February/13/2008 Status: Offline Points: 23679 |
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Being a tester of munitions and their performance by profession, I am not allowed to "create" data. I answered the question as asked... discounting resistance/drag, wind. There was no mention of it and no facts were included in the problem statement.
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Opinion,untempered by fact,is ignorance.
There are some who do not fear death... for they are more afraid of not really living |
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Alan Robertson
Optics Master Joined: October/31/2009 Location: Oklahoma Status: Offline Points: 1763 |
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Actually, time isn't construed as changing in different quantum realities/dimensions/levels, so much as distance/size, with distance being the only illusory aspect and time as a constant. Or something. |
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"Garg'n uair dhuisgear"
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Kickboxer
MODERATOR Moderator Joined: February/13/2008 Status: Offline Points: 23679 |
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This is basiclly true... however the most "commonly stated" terms 9.81m/s^2 vs. the most common English of 32 ft/s^2, the metric is most accurately expressed and what I most often use. I believe I could come close at 32.2 ft/s^2, but just never have used it.
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Opinion,untempered by fact,is ignorance.
There are some who do not fear death... for they are more afraid of not really living |
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Dale Clifford
Optics Jedi Knight Joined: July/04/2004 Location: United States Status: Offline Points: 5087 |
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ballistic curves are basically log equations and as such have closed forms. When doing numerical analysis using diffference equations or differential equations, the analyst will try to fit the computed data with a closed form to arrive at an error. This is the basis of Patagonia's software and there complaint against other forms of software on the market. Patagonia computes using curve fitting techniques derived from real time flight velocities vs. location.
Now for a really, really hard math question ---
Prove that -1 x -1 = +1 (seriously this is hard) the answer is not the obvious cartisian graph solution
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I love little league baseball-- it keeps the kids out of the house
Yogi Bera |
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Kickboxer
MODERATOR Moderator Joined: February/13/2008 Status: Offline Points: 23679 |
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the proof is not difficult, just tedious... time consuming... after you prove -1 * x = -x, it is just details...
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Opinion,untempered by fact,is ignorance.
There are some who do not fear death... for they are more afraid of not really living |
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Dale Clifford
Optics Jedi Knight Joined: July/04/2004 Location: United States Status: Offline Points: 5087 |
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won"t work , it assumes that -1 x -1 is correct--it will lead to a logical nor statement stating
if you believe neither this or that is incorrect then so and so must be
make a long story short and save the suspense of everyone hanging on their sets, (opps seats)
the statement isonly true in convergent algebras and must be proven using algebraic ring theory.
thus the saying "algebraists love closed sets" (have to go to set theory with the proof)
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I love little league baseball-- it keeps the kids out of the house
Yogi Bera |
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Alan Robertson
Optics Master Joined: October/31/2009 Location: Oklahoma Status: Offline Points: 1763 |
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Hope you guys aren't closet topologists trying to tell the difference between your coffee cup and your donut hole.
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"Garg'n uair dhuisgear"
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Dale Clifford
Optics Jedi Knight Joined: July/04/2004 Location: United States Status: Offline Points: 5087 |
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they are the same --- 2 - manifolds
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I love little league baseball-- it keeps the kids out of the house
Yogi Bera |
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dsr
Optics Apprentice Joined: May/31/2007 Location: United States Status: Offline Points: 244 |
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410 yrds assuming constant velocity from muzzle. ( as first order approximation) with g=32.17 ft/s^2. The solution is a vector quantity and can be solved independently for vertical and horizontal components. The vertical solution controls the answer by being the first at a time ~ 0.431 seconds which sets the time of flight before the one second mark. Providing a distance approximately 410 yards down range. Further information only refines the the accuracy of the answer.
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8shots
Optics Jedi Knight Lord Of The Flies Joined: March/14/2007 Location: South Africa Status: Offline Points: 6253 |
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t= sqrt(0.9144x2/9.81)
=.432sec flight time
at 950yds per sec
=410 yds
.9144m being 1yard
9.81 being speed of gravity in m/s^2.
Essentially I was looking for equating flight time of the bullet with the flight time of a dropped bullet.
Ok , back to coffee and doughnuts Edited by 8shots - February/07/2012 at 04:05 |
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Kickboxer
MODERATOR Moderator Joined: February/13/2008 Status: Offline Points: 23679 |
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totally incorrect
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Opinion,untempered by fact,is ignorance.
There are some who do not fear death... for they are more afraid of not really living |
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Kickboxer
MODERATOR Moderator Joined: February/13/2008 Status: Offline Points: 23679 |
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As I said earlier, depends upon rounding assumptions. 410 yds is as good as any... and very acceptable..
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Opinion,untempered by fact,is ignorance.
There are some who do not fear death... for they are more afraid of not really living |
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trigger29
Optics Master Extraordinaire X = 180 Y = 90 (X+Pyro)+(Y-Pyro) = ? Joined: September/29/2007 Location: South Dakota Status: Offline Points: 4353 |
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I understand the bullet will hit the dirt at exactly the same time as a bullet dropped straight down. This is not a mystery to any of us. In the real world though, at least where I live, there is air that will slow BOTH bullets....... The fired one will not go as far, as drag will slow it down, and the one dropped will also encounter wind resistance before hitting the dirt.
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"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed." |
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Alan Robertson
Optics Master Joined: October/31/2009 Location: Oklahoma Status: Offline Points: 1763 |
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What the hell am I doin' in this thread? |
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"Garg'n uair dhuisgear"
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Dale Clifford
Optics Jedi Knight Joined: July/04/2004 Location: United States Status: Offline Points: 5087 |
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Jeez- a 3-in-1 screw. Thats a lot to think about.
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I love little league baseball-- it keeps the kids out of the house
Yogi Bera |
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SD Dog
Optics Master Extraordinaire OT Scratching Post Joined: February/28/2008 Status: Offline Points: 4177 |
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Where's Ed? Kind of his speed.
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If nobody ever said anything unless he knew what he was talking about, a ghastly hush would descend upon the earth. AP Herbert
Stupidity & ignorance have been the foundation for many certainties. |
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trigger29
Optics Master Extraordinaire X = 180 Y = 90 (X+Pyro)+(Y-Pyro) = ? Joined: September/29/2007 Location: South Dakota Status: Offline Points: 4353 |
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A 3-in-1 screw maybe.......... The math, not so much.
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"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed." |
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