Author Topic: Pellet 800 fps & bullet 3000 fps ?  (Read 3935 times)

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Pellet 800 fps & bullet 3000 fps ?
« on: August 06, 2006, 10:20:01 PM »
Random quote: if a pellet is going 800fps, and a bullet shot at the same time is going 3000fps, with a level shot, which one hits the ground first?
- (Added by: DanoInTx)
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My little brain thinks they will hit the ground at the same time.
But it does not sound right. :0

  • Guest
RE: Pellet 800 fps & bullet 3000 fps ?
« Reply #1 on: August 06, 2006, 10:59:24 PM »
They both hit the ground at the same time. One is just two miles farther down the road.
Bart.

Offline ribbonstone

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RE: Pellet 800 fps & bullet 3000 fps ?
« Reply #2 on: August 06, 2006, 11:05:34 PM »
Wuthout getting into issues of possible lift thrugh roatation adn wind direction, this is the classic physic's class example....fired level, horizonatal vel. doesn't effect vertical vel. (gravity in this case)...so if fired from the same height over level ground, will hit ground (vertical velocity) at the same time.

Of course that only really works in a vaccuume, are little games rotating cylnders play in atmosphere that can change that by a small amounts.
Robert

Offline vinceb

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IF ya wanna split hairs...
« Reply #3 on: August 07, 2006, 03:33:04 AM »
...and remember that we live on a round ball, not a "flat earth"....

The 3000fps bullets takes longer to hit the ground, about 20ms (.02 sec) than the slower speed pellet, assuming it's fired from about a 5' height off the ground. Why? Because of the curvature of the earth's surface, the earth starts "falling away" from the bullet as the bullet travels in a horizontal direction... the further the bullet travels, it actually has farther to drop.

Theoretically speaking, one can shoot a bullet so fast that it NEVER hits the earth - that's called "escape velocity". NASA does it all the time (sorta)...

Offline Cvan

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RE: IF ya wanna split hairs...I'm bald!
« Reply #4 on: August 07, 2006, 05:22:08 AM »
This is of course if both objects are shaped the same and are of the same mass. Correct?

Offline vinceb

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RE: IF ya wanna split hairs...I'm bald!
« Reply #5 on: August 07, 2006, 08:32:56 AM »
That's not very significant, since the vertical drop (and vertical velocity) we're talking about is rather small and the densities are (roughly) comparable, the atmospheric phenomena of air resistance and boyancy don't really come into play.

The projectiles will only take on the order of .6 sec to hit the ground, at a speed of about 19 feet/sec, or about 12-13mph.

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RE: IF ya wanna split hairs...
« Reply #6 on: August 08, 2006, 03:06:07 AM »
Quote
vinceb - 8/6/2006  11:33 AM

...and remember that we live on a round ball, not a "flat earth"....

The 3000fps bullets takes longer to hit the ground, about 20ms (.02 sec) than the slower speed pellet, assuming it's fired from about a 5' height off the ground. Why? Because of the curvature of the earth's surface, the earth starts "falling away" from the bullet as the bullet travels in a horizontal direction... the further the bullet travels, it actually has farther to drop.

Theoretically speaking, one can shoot a bullet so fast that it NEVER hits the earth - that's called "escape velocity". NASA does it all the time (sorta)...


I realy doudt the curvature of the earth is a reasonable factor to consider.
The curve is small enough that, over the distances  we are talking about it would be completely swamped by local variations...random rises and falls in ground level...hills.

  • Guest
Re: Pellet 800 fps & bullet 3000 fps ?
« Reply #7 on: August 08, 2006, 09:10:43 AM »
Let's see if I got this right...

I believe that the earth curves approximately 8 inches per mile.

One mile is 1760 yards, so over a normal shot of say, 25 yards,  one could expect a drop of roughly 0.1 inches due to durvature of the earth.

so grab those mildots and make your corrections! =D

Offline -=ed

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RE: Pellet 800 fps & bullet 3000 fps ?
« Reply #8 on: August 08, 2006, 10:27:26 AM »
If we're trying to get *really* accurate, I think you're all forgetting that gravity varies from point to point depending what kind of material the earth is made of at any given point.
This could swamp the curvature factor in mining areas, I'd think.

 :p  :p
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-=ed..................... \"...and in our dark despair, against our will... wisdom comes...\"

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Offline DanoInTx

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Re: Pellet 800 fps & bullet 3000 fps ?
« Reply #9 on: August 09, 2006, 04:48:58 PM »
Ok, let me end this since I instigated it in the first place:)

Let's just ASSUME that our tiny parcel of land has been calibrated from crust to magma core for consistency, and has been completely flattened smooth as glass.  The projectiles are of the exact same shape(round), and there is no air, astronauts or squirrels in the way, the barrels have been leveled with special atomic calipers and the triggers are both being fired electronically from the same switch, which is wired in paralell to the triggers.  So all we are dealing with is forward velocity and gravity!  I would have put this ALL in my quote if I had more time and space to write it.

they both hit the ground at the same time, no split hairs, or logs, or cheerleaders doing the splits.

Dan
Dan

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Offline vinceb

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In other words....
« Reply #10 on: August 10, 2006, 05:55:36 AM »
....the acceleration due to gravity (in a vacuum) is independent of mass.


Offline -=ed

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RE: In other words....
« Reply #11 on: August 10, 2006, 07:33:28 AM »

I'd go with that.
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-=ed..................... \"...and in our dark despair, against our will... wisdom comes...\"

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Offline DanoInTx

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Yay!!! We have a consensus! (NT)
« Reply #12 on: August 10, 2006, 11:17:49 AM »
I said no text!
Dan

Current shooters: Beeman HW97K .177 with Hawke Eclipse 4x16x50SFAO and Steve C. stock, Beeman R9 .177 with Hawke Airmax 4-12x40AO and Gene\'s Midas touch, Air Arms S200 with Bushnell Banner 6x24x40AO Rowan brass bling and Steve C. custom stock, BAM B25, BAM B40 .177 with BSA 3x12x44AO, Benjamin Marauder .22, Benjamin 397 pumper.

\"repeat this mantra:
Air gunzzzzzz, air gunzzzzzz, air gunzzzzzzz!!!  ...You will feel better\" T.E.C.2008