E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > Everything Else > The Off-Topic > General Off-Topic

General Off-Topic
Everything not about BMWs. Posts must be "primetime" safe and in good taste. You must be logged in to see sub-forums.
Click here to browse all new posts.

View Poll Results: Which Bullet will hit the ground first?
The bullet in his hand 31 28.70%
The bullet fired from the gun 4 3.70%
Both at the same time 70 64.81%
No idea. Stupid bloody question 3 2.78%
Voters: 108. You may not vote on this poll

Reply
 
Thread Tools Search this Thread Rating: Thread Rating: 1 votes, 5.00 average. Display Modes
Old 07-05-2012, 12:55 AM   #21
gueste46
Banned User
 
Join Date: May 2011
Posts: 1,607
Most of you picked the correct answer. Both at the same time. A couple of people read too much into the question, talking about the earth's curvature and so on. A bullet fired from a handgun does not travel fast enough nor far enough to make this a factor.

The previous post about the book and the feather gave me a headache.
gueste46 is offline   Reply With Quote
Old 07-05-2012, 01:00 AM   #22
CollinsE90
Registered User
 
Join Date: Mar 2009
Location: The bar
Posts: 340
My Ride: 330i
Quote:
Originally Posted by ImPulSe View Post
The same can be done with a book and a feather
In a vacuum. Feather experiences air resistance.
__________________
CollinsE90 is offline   Reply With Quote
Old 07-05-2012, 02:46 AM   #23
deafboy
Registered User
 
Join Date: Sep 2005
Location: Blaine, WA
Posts: 26,609
My Ride: 2000 323Ci
Both or who knows... doesn't say where he is standing.

And for that matter, he could shoot over the edge of a cliff where the ground is lower or something of the like.




both at the same time is conditions can be assumed fair. lol.
__________________
-Cole aka bigtall*****

Quote:
Originally Posted by Owtlaw333 View Post
You'll always be pretty in my eyes, Cole :luv:
Quote:
Originally Posted by Chrissspyy View Post
i was like passed out while she's shoving the entire bar in my mouth. :rofl: :rofl:
deafboy is offline   Reply With Quote
Old 07-05-2012, 05:09 AM   #24
steve.k
Registered User
 
Join Date: Dec 2010
Location: NSW, Australia
Posts: 1,329
My Ride: 05' 325Ci, 13' WRX
LOL i didn't read the first post and just assumed the bullet fired from the gun was aimed directly at the ground... so yeah, the '1' vote for 'bullet fired from gun' was me Lol.
steve.k is offline   Reply With Quote
Old 07-05-2012, 08:18 AM   #25
cowmoo32
drunken science
 
cowmoo32's Avatar
 
Join Date: Jul 2003
Location: Raleigh, NC
Posts: 5,533
My Ride: Trek 1.5
Quote:
Originally Posted by Tutankhamon View Post
Force applied to a fired bullet I feel would make that bullet slower to hit the ground than just a dropped bullet. My reasoning is the net force pushing the bullet to the ground is less than gravity itself.

Dropping a bullet has only gravity acting on it so net force will roughly be gravity.
Firing a bullet still has the same gravity acting on it but also a horizontal force component. Once the net force is calculated, it will be less than that of gravity (thinking of a triangular force diagram here)
No. You can resolve horizontal and vertical acceleration into a single acceleration that will be pointed down and in the direction of travel, but without anything pushing up on the bullet, gravity acts as it normally would.

m = mass of bullet
a = acceleration in direction of travel
g = acceleration due to gravity
__________________

flickher

What's this about a brownie in motion?
cowmoo32 is offline   Reply With Quote
Old 07-05-2012, 12:29 PM   #26
brew
Registered User
 
Join Date: May 2003
Location: Central Oregon
Posts: 348
My Ride: F150 X5 MR2
Quote:
Originally Posted by Constantine View Post
Most of you picked the correct answer. Both at the same time. A couple of people read too much into the question, talking about the earth's curvature and so on. A bullet fired from a handgun does not travel fast enough nor far enough to make this a factor.

The previous post about the book and the feather gave me a headache.
BS - the curvature of the earth means that the bullet fired horizontally must fall farther to hit the ground than the bullet dropped from his hand. 5 feet or 500 feet, it still makes a measurable difference. You're just rounding off the difference to claim its the same.

With 500 feet of travel, the earth's curvature adds an extra 3.75 inches to the distance that the bullet must fall to hit the ground.

Last edited by brew; 07-05-2012 at 12:30 PM.
brew is offline   Reply With Quote
Old 07-05-2012, 12:31 PM   #27
rohde88
Registered User
 
rohde88's Avatar
 
Join Date: Jan 2004
Location: Dallas, TX
Posts: 855
My Ride: S2000
Quote:
Originally Posted by brew View Post
BS - the curvature of the earth means that the bullet fired horizontally must fall farther to hit the ground than the bullet dropped from his hand. 5 feet or 500 feet, it still makes a measurable difference. You're just rounding off the difference to claim its the same.

With 500 feet of travel, the earth's curvature adds an extra 3.75 inches to the distance that the bullet must fall to hit the ground.
Brew-I don't know about you, but I measure 1" bullets with a 12" increment ruler.
__________________
-Ron
rohde88 is offline   Reply With Quote
Old 07-05-2012, 12:32 PM   #28
casino is no lie
Registered User
 
Join Date: Jan 2012
Location: CDT
Posts: 76
My Ride: M54B30
Assuming it takes places in a vacuum... the same time.
__________________
casino is no lie is offline   Reply With Quote
Old 07-05-2012, 12:37 PM   #29
cowmoo32
drunken science
 
cowmoo32's Avatar
 
Join Date: Jul 2003
Location: Raleigh, NC
Posts: 5,533
My Ride: Trek 1.5
Quote:
Originally Posted by brew View Post
BS - the curvature of the earth means that the bullet fired horizontally must fall farther to hit the ground than the bullet dropped from his hand. 5 feet or 500 feet, it still makes a measurable difference. You're just rounding off the difference to claim its the same.

With 500 feet of travel, the earth's curvature adds an extra 3.75 inches to the distance that the bullet must fall to hit the ground.
Where did you get that from?


This is a simple problem and they will hit at the same time so long as the gun is fired perfectly normal to the ground.
__________________

flickher

What's this about a brownie in motion?
cowmoo32 is offline   Reply With Quote
Old 07-05-2012, 02:20 PM   #30
brew
Registered User
 
Join Date: May 2003
Location: Central Oregon
Posts: 348
My Ride: F150 X5 MR2
Quote:
Originally Posted by cowmoo32 View Post
Where did you get that from?


This is a simple problem and they will hit at the same time so long as the gun is fired perfectly normal to the ground.
Well, it's not entirely accurate, but I simply extrapolated the old rule of thumb of 5 meters of drop at 8,000 meters.

They'll hit at the same time only if the earth is flat.
brew is offline   Reply With Quote
Old 07-05-2012, 03:21 PM   #31
325rider
Registered User
 
Join Date: May 2005
Location: Miami, FL
Posts: 2,567
My Ride: gone, not forgotten
Send a message via AIM to 325rider
Literally they cannot hit at the same time because the traveling bullet will fall an extra inch or whatever amount of height, but significantly so, more than the stationary one because the earth curves.

If you argue against that ur a moron
__________________


Schrick 264/248 | Ebay Headers | AA dyno tune | SSR GT2 18x9 | 3.46 | Full OEM Mtech 2

My Fitness YouTube Channel!!! Thanks for all the support I am GRATEFUL

http://www.youtube.com/channel/UCozwn8gNwXQVuG0se8cTpUQ
325rider is offline   Reply With Quote
Old 07-05-2012, 03:26 PM   #32
cowmoo32
drunken science
 
cowmoo32's Avatar
 
Join Date: Jul 2003
Location: Raleigh, NC
Posts: 5,533
My Ride: Trek 1.5
Quote:
Originally Posted by brew View Post
Well, it's not entirely accurate, but I simply extrapolated the old rule of thumb of 5 meters of drop at 8,000 meters.

They'll hit at the same time only if the earth is flat.
Quote:
Originally Posted by 325rider View Post
Literally they cannot hit at the same time because the traveling bullet will fall an extra inch or whatever amount of height, but significantly so, more than the stationary one because the earth curves.

If you argue against that ur a moron
What you're forgetting is that gravity causes the bullet to curve around the earth; it doesn't just shoot straight off, gaining height as it flies. If you gave it enough energy then it would, but then we're talking escape velocities.



Solve for t in the first equation. Viy = 0. Notice the only variable affecting the time is vertical acceleration AKA gravity. Both bullets have the same mass and experience the same vertical acceleration in the direction of the ground. They will hit at the same time.
__________________

flickher

What's this about a brownie in motion?

Last edited by cowmoo32; 07-05-2012 at 03:29 PM.
cowmoo32 is offline   Reply With Quote
Old 07-05-2012, 03:48 PM   #33
yousharenow
Registered User
 
Join Date: Mar 2010
Location: ATL
Posts: 215
My Ride: E46 ZHP
Send a message via AIM to yousharenow
They hit at the same time.
yousharenow is offline   Reply With Quote
Old 07-05-2012, 03:57 PM   #34
casino is no lie
Registered User
 
Join Date: Jan 2012
Location: CDT
Posts: 76
My Ride: M54B30
Quote:
Originally Posted by cowmoo32 View Post
What you're forgetting is that gravity causes the bullet to curve around the earth; it doesn't just shoot straight off, gaining height as it flies. If you gave it enough energy then it would, but then we're talking escape velocities.



Solve for t in the first equation. Viy = 0. Notice the only variable affecting the time is vertical acceleration AKA gravity. Both bullets have the same mass and experience the same vertical acceleration in the direction of the ground. They will hit at the same time.
__________________
casino is no lie is offline   Reply With Quote
Old 07-05-2012, 04:43 PM   #35
brew
Registered User
 
Join Date: May 2003
Location: Central Oregon
Posts: 348
My Ride: F150 X5 MR2
Quote:
Originally Posted by cowmoo32 View Post
What you're forgetting is that gravity causes the bullet to curve around the earth; it doesn't just shoot straight off, gaining height as it flies. If you gave it enough energy then it would, but then we're talking escape velocities.



Solve for t in the first equation. Viy = 0. Notice the only variable affecting the time is vertical acceleration AKA gravity. Both bullets have the same mass and experience the same vertical acceleration in the direction of the ground. They will hit at the same time.
But the bullet shot from the gun has further distance to travel to the ground. It's exactly like if you dropped two bullets, one onto flat ground and one into a 4" hole in the same ground. The bullet falling into the hole takes longer to hit the ground.
brew is offline   Reply With Quote
Old 07-05-2012, 04:53 PM   #36
cowmoo32
drunken science
 
cowmoo32's Avatar
 
Join Date: Jul 2003
Location: Raleigh, NC
Posts: 5,533
My Ride: Trek 1.5
Quote:
Originally Posted by brew View Post
But the bullet shot from the gun has further distance to travel to the ground. It's exactly like if you dropped two bullets, one onto flat ground and one into a 4" hole in the same ground. The bullet falling into the hole takes longer to hit the ground.
The acceleration due to gravity keeps the bullet falling at a steady rate toward earth and the bullet follows the curvature of the earth. The bullet does not gain any height when it is fired from the gun. As I said earlier, give the bullet enough energy (velocity) and it will go into orbit if you fire it horizontally.



I understand what you're thinking, and it's a logical thought, but that's not how it works. Think of it like this: An airplane takes off and holds altitude and bearing. Does it continue to gain altitude as it follows a straight path? No, it follows the curvature of the earth. The bullet works in the same manner, except it falls after leaving the barrel.
__________________

flickher

What's this about a brownie in motion?

Last edited by cowmoo32; 07-05-2012 at 04:56 PM.
cowmoo32 is offline   Reply With Quote
Old 07-05-2012, 05:09 PM   #37
brew
Registered User
 
Join Date: May 2003
Location: Central Oregon
Posts: 348
My Ride: F150 X5 MR2
Quote:
Originally Posted by cowmoo32 View Post
The acceleration due to gravity keeps the bullet falling at a steady rate toward earth and the bullet follows the curvature of the earth. The bullet does not gain any height when it is fired from the gun. As I said earlier, give the bullet enough energy (velocity) and it will go into orbit if you fire it horizontally.
Are you're saying that if you give a bullet enough energy, it will go into orbit and therefore never hit the ground - but if you give it just slightly less energy it will hit the ground as if it were dropped? There's no middle ground? It's like a light switch? That makes no sense. Imagine one bullet that goes into orbit, another that travels 4 times around the earth before hitting the ground, another that goes 1/4 of the way around the earth before it hits the ground . . another that goes 1,000 feet before hitting the ground and then another that goes 0 feet (dropped). The further the bullet travels, the greater the distance between a true horizontal path and the surface of the earth, the longer it takes to hit the ground.

In your picture, look at A and B. B falls a greater distance from the horizontal path. It has to take longer to hit the ground.
Quote:
Originally Posted by cowmoo32 View Post
I understand what you're thinking, and it's a logical thought, but that's not how it works. Think of it like this: An airplane takes off and holds altitude and bearing. Does it continue to gain altitude as it follows a straight path? No, it follows the curvature of the earth. The bullet works in the same manner, except it falls after leaving the barrel.
The airplane is not following a straight path, it is constantly changing it's direction of travel towards the earth.

Last edited by brew; 07-05-2012 at 05:11 PM.
brew is offline   Reply With Quote
Old 07-05-2012, 05:36 PM   #38
cowmoo32
drunken science
 
cowmoo32's Avatar
 
Join Date: Jul 2003
Location: Raleigh, NC
Posts: 5,533
My Ride: Trek 1.5
Quote:
Originally Posted by brew View Post
Are you're saying that if you give a bullet enough energy, it will go into orbit and therefore never hit the ground - but if you give it just slightly less energy it will hit the ground as if it were dropped? There's no middle ground? It's like a light switch? That makes no sense.
I never said it was intuitive, but that's exactly how it works. There is a threshold velocity that, if crossed, will send the bullet into orbit. Anything less will result in a crash back to earth. I was wrong. After doing some more reading, it appears there is a middle ground and as you approach escape velocity, it does take longer to get to the ground (again, not totally intuitive). If we're talking regular guns then it isn't an issue, but when you start getting into the territories of blasting things into orbit, it does come into play. Apparently though, it's impossible to laterally launch anything into orbit due to friction with the air, so we launch straight up instead.



I'm 99% sure mythbusters tested this, let me see if I can find a clip.
edit:
__________________

flickher

What's this about a brownie in motion?

Last edited by cowmoo32; 07-05-2012 at 05:46 PM.
cowmoo32 is offline   Reply With Quote
Old 07-05-2012, 05:58 PM   #39
brew
Registered User
 
Join Date: May 2003
Location: Central Oregon
Posts: 348
My Ride: F150 X5 MR2
Quote:
Originally Posted by cowmoo32 View Post
I never said it was intuitive, but that's exactly how it works. There is a threshold velocity that, if crossed, will send the bullet into orbit. Anything less will result in a crash back to earth. I was wrong. After doing some more reading, it appears there is a middle ground and as you approach escape velocity, it does take longer to get to the ground (again, not totally intuitive). If we're talking regular guns then it isn't an issue, but when you start getting into the territories of blasting things into orbit, it does come into play. Apparently though, it's impossible to laterally launch anything into orbit due to friction with the air, so we launch straight up instead.

It's enough of an issue that naval gunships have been factoring in the earth's curvature for fire control since at least WWII. But since the question here was simply "which one hits the ground first?", the answer is " the one simply dropped". It may not be enough of a difference to make it "an issue", but it still hits first.
brew is offline   Reply With Quote
Old 07-05-2012, 06:16 PM   #40
trippinbillies4
Registered User
 
trippinbillies4's Avatar
 
Join Date: Jul 2004
Location: Cincinnati, OH
Posts: 836
My Ride: '02 Mini, '13 FR-S
Quote:
Originally Posted by cowmoo32 View Post
I never said it was intuitive, but that's exactly how it works. There is a threshold velocity that, if crossed, will send the bullet into orbit. Anything less will result in a crash back to earth. I was wrong. After doing some more reading, it appears there is a middle ground and as you approach escape velocity, it does take longer to get to the ground (again, not totally intuitive). If we're talking regular guns then it isn't an issue, but when you start getting into the territories of blasting things into orbit, it does come into play. Apparently though, it's impossible to laterally launch anything into orbit due to friction with the air, so we launch straight up instead.



I'm 99% sure mythbusters tested this, let me see if I can find a clip.
edit:
360' for a bullet to drop when fired out of a gun? What the hell are they shooting? I haven't watched the full episode, but that has to be an extremely light load in that cartridge. A typical .45 will travel WAY farther than 360' when shot perfectly level.
__________________
__________________________________________________

'02 Mini Cooper #40HS, '13 Scion FR-S #40CS, '12 Ducati SF848
trippinbillies4 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON





All times are GMT -5. The time now is 03:54 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use