Defeating gravity!

BIGREDD

BIGREDD

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Well I have been thinking about this for a few days now that I have calmed myself I believe it is time to discuss it with my peers.:cool:
At a recent training course I had to make a presentation on trajectory. As part of my definition I stated that when the projectile leaves the barrel it immediately begins to fall due to the effect of gravity.
I was not speaking about line of sight or bore line... but only the simple physics of gravity when I made this statement.
Well when I was done my presentation the Trainer criticized me for not knowing my facts. He stated that when a bullet leaves the muzzle it actually defies gravity for a short distance. I could not help but question him about this logic and he went on to explain that the bullet will "super defeat" gravity and that this was a fact.:eek:
At this moment I nearly bit a hole through my cheek and decided not to hijack the class with an argument. I noticed some of the other trainees looking incredulous at the instructor and I could tell they were wondering what the hell he was talking about.:rolleyes:

So what do you fellas think? Does a bullet defy (super defeat:rolleyes:) gravity when it exits the barrel? Or is this a common myth propagated by those who don't understand line of sight and trajectory?:)
 
I had this argument just the other day at work. Heres what I found on my search to prove him wrong.

http://www.school-for-champions.com/science/gravity.htm

Acceleration independent of mass
One surprising characteristic of the force of gravity is that the acceleration it causes in falling bodies it independent of the mass of the object.

In other words, a 5-pound weight would fall at the same rate as a 10-pound weight. If dropped from the same height, they would take the same time to hit the ground. Of course, in dropping a lightweight object, air resistance often will slow the object down more than a heavier object.

Not only does is the acceleration of gravity independent of the mass of an object, but it is also independent of the velocity of the object parallel to the ground.

In other words, it an object is traveling at some velocity parallel to the ground, it will fall at the same rate as a stationary object. Thus a bullet shot from a gun will hit the ground at the same time as one that was simply dropped from the same height.

In conclusion
All objects attract each other through the force of gravity. The acceleration caused by gravity is independent of the mass or weight of an object, as well as any motion perpendicular to the ground.
Click to expand...
 
Maybe laddie was confused because a projectile is launched with a slight upward angle to overcome the immediate and inescapable effect of gravity.
 
It never ceases to amaze me that there are still people out there ( even trainers!) that beleive that crap.
We learn about gravity in grade school, yet you get so-called "experts"spouting crap like that every day!
You were right to keep yer yap shut BR, becuase it doesn't matter what you think, but what the INSTRUCTOR WANTS TO HEAR!!

Simply stunning that they actually let guys like that teach anything.

I remember a story my older brother told me when he was in cadets at the rifle coach course at Bordan in the 60's.
He contradicted a cadre's statement on something about breathing ( I think it was), and was asked qurtly "Perhaps you would like come up here and instruct the class?"

"Absolutely!" was his reply.
BAD MOVE!!:D
I have no doubt the instuctor was wrong as my brother at the time aready had many years of excellent instruction under his belt and was a National smallbore Champion....!
Cat
 
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Well the thing that amazes me the most is that this instructor was was extremely qualified and one of the best teachers I have ever had.
The fact that we all can be wrong or misinformed about certain subjects is certainly hard to accept for some of us.
Nevertheless I will certainly contact this instructor with some reference material... not because I feel slighted... but so that he can teach the truth!
 
From the teaching standpoint, he was wrong to correct you in front of the class. The particular piece of information he told the class, apart from being silly, was irrelevant to the CFSC. He undermined either his, or your credibility, depending on how informed students were.
 
Was your trainer's name Marc Garneau?
That would explain his dubious "Super-duper Defeating Gravity" theory...:rolleyes:
Reminds me those old geezers that always justified their misses by "When shooting over water, you have to aim high because water attracts bullets; it is known fact, young lad..."
PP.
 
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BigRedd:

Why not admit to the "Trainer" in your most humble manner, that you can't seem to grasp the "facts" as he's related them, and to be able to understand
the theories relating to " super defeating gravity', if he would be so kind as to help you be able to teach the truth, by finding you some published information on the matter ??? Would really like to see what he's able to dig up. Maybe while he's at it, he can also find the recipe for converting lead into gold for us too !!!
 
BIGREDD said:
when the projectile leaves the barrel it immediately begins to fall due to the effect of gravity.

Well when I was done my presentation the Trainer criticized me for not knowing my facts. He stated that when a bullet leaves the muzzle it actually defies gravity for a short distance.
Click to expand...

As soon as the projectile leaves the barrel, there is a downward force (gravity) acting on it. It may still be moving upward due the direction the barrel was pointed in, but it does not defy gravity. I think your instruction isn't 100% clear on his physics. Back to grade 11 for him.
 
Well just show him what the AMERICAN army teaches!!!


http://www.usarc.army.mil/417TransDet/appf.htm



they make american instructor know!!!

Instructors/trainers must be knowledgeable on the effects of wind and gravity, ballistics, the elevation and windage rule, and bullet dispersion as they apply to firing proficiency

Your welcome
 
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When I took my CFASC the instructor was trying to impress on the students the amount of force that's required to move the bullet out of the firearm. He stated something to the effect the the pressures were up around 5000 psi in centerfire rifles.

I asked if he actually meant 50,000 psi to which he responded that that was impossible - the gun would blow up at those pressures. He was quite agitated and I withdrew from the conversation.

Oh well...
 
I certainly think a trip back to high school is in order.

Fired at any angle gravity still immediatly acts upon the bullet accelerating it towards the center of the earth. In fact gravity has never stopped acting on the bullet it just does not get a chance to affect the bullets path until it is no longer supported by the barrel.
 
My understanding is that gravity is constant and the faster a projectile is tossed over the same distance the less effect gravity will play against its path. A bullet tossed at 500 feet per second (FPS) will spend more time covering a measured distance to target and have a greater amount of flight time to target in which gravity will effect its horizontal path, than say one tossed at 3000 fps. This instructor obviously has been cleaning to many guns in a unventilated room!
 
well bullets do when shot arch a bit so if you dropped a bullet at the bbr height the bullet would in fact hit after the dropped one.
so to get them hitting the ground at the same time you would have to drop the bullet a few inches above the bbr.
ttyal
Riley
 
death-junky said:
well bullets do when shot arch a bit so if you dropped a bullet at the bbr height the bullet would in fact hit after the dropped one.
so to get them hitting the ground at the same time you would have to drop the bullet a few inches above the bbr.
ttyal
Riley
Click to expand...

Well not really. NOTHING can DEFY GRAVITY.

The second the bullet leaves the barrel it is affected by gravity. if shot strait up in the air, that a bullet starts to slow the second it leaves the barrel is proof.

You cant defy cheat or anything else gravity. Unless you happen to have a black hole in your pocket, but that is a different discussion.

You can use mechanical force to ofset the force of gravity, But you are applying a constant force greater then gravity. The millisecond the external force is removed gravity takes over again. Ask any pilot whose engines quit!!!
 
death-junky said:
well bullets do when shot arch a bit so if you dropped a bullet at the bbr height the bullet would in fact hit after the dropped one.
so to get them hitting the ground at the same time you would have to drop the bullet a few inches above the bbr.
ttyal
Riley
Click to expand...

Not quite.
See below.

In other words, it an object is traveling at some velocity parallel to the ground, it will fall at the same rate as a stationary object. Thus a bullet shot from a gun will hit the ground at the same time as one that was simply dropped from the same height.
Click to expand...
 
I think I am missing something, I agree your prof needs a boot to the nads for his defiance of gravity theory so disregard that from this request for clarification.
scenerio as described by
BIGREDD said:
, "when the projectile leaves the barrel it immediately begins to fall due to the effect of gravity"
Click to expand...
To me this says that if you are standing stationary holding an object (for the sake of arguement lets make it an orange) in the palm of your hand held out from your torso palm up, and in an upward motion throw the orange into the air - Is the orange falling from the result of gravity, despite moving upward and away from the source of gravity?
or
Is gravity impairing the progress of the force of enertia until the force is overcome and then then orange begins to fall due to gravity?
I liken these two scenerios as the same. I don't see the bullet dropping until it stops moving away from the gravity source but I do see it being affected by gravity from the the point of firing, whether it be muzzle or chamber is to be left for another debate.
 
Chilly Willy said:
My understanding is that gravity is constant and the faster a projectile is tossed over the same distance the less effect gravity will play against its path. A bullet tossed at 500 feet per second (FPS) will spend more time covering a measured distance to target and have a greater amount of flight time to target in which gravity will effect its horizontal path, than say one tossed at 3000 fps. This instructor obviously has been cleaning to many guns in a unventilated room!
Click to expand...

Gravity is an acceleration constant. 32.2 feet per second, per second, or 32.2 feet per second squared. Therefore, if a bullet is fired HORIZONTALLY, it begins to drop at a rate of 32.2 feet per second squared, as soon as it is no longer vertically supported by the barrel. If it's time in flight is 0.5 seconds, then the bullet drop would be the same as a slug dropped from a stationary posisition, for 0.5 seconds. That is why when velocity increases, time of flight decreases, and bullet drop decreases.
 
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